147 claims taken apart
Is that actually true?
A headline, a documentary, a post from a friend. These pages take a popular claim apart and show what the evidence really supports — including when the honest answer is that researchers do not agree.
Why so many corrections?
Because of what we choose to look at. A claim earns a page here when it is uncertain, exaggerated, endlessly repeated, or commonly misunderstood — nobody needs us to confirm that otters eat fish. So this collection is a set of claims picked for being wobbly, not a sample of everything people say about nature, and the mix of verdicts below says nothing about how often ordinary claims are right.
It holds up · 3
Things that turn out to be true
Some of the strangest things people repeat about nature are simply correct. These are the ones where the popular version and the evidence agree — occasionally with the research being the stranger of the two.
Do wild birds really lead people to bees’ nests?
It is true, and the measurements went further than the story. Guided searches find nests far faster than unguided ones, and playing back the specialised call honey-gatherers use more than doubles the chance of being guided — against other human sounds.
Where you may have met it: travel writing and natural-history booksRead on- Supported
Do whales have dialects?
Yes, in the sense biologists use the word: stable, group-specific vocal repertoires learned from other members of the group. Killer whale pods keep distinct call repertoires for decades, and sperm whale clans sharing the same water go on sounding different. It says nothing about whether the calls mean anything.
- Supported
Does every tiger have a unique stripe pattern?
Yes, and it is not trivia. Individual identification from stripe patterns is the basis of essentially every published estimate of how many wild tigers there are.
Nearly · 43
True, and then stretched
The biggest category, and the most useful one to understand. Something real sits underneath each of these and the retelling has pushed it past what was shown — usually by dropping the species it was found in, or the word "some".
Did mitochondria used to be bacteria?
The ancestry is right and among the best-evidenced historical claims in biology. The present tense is not: most of the ancestral genes now sit in your nucleus, and a mitochondrion cannot live independently of the cell.
Where you may have met it: popular science writing and biology teachingRead on- Mostly supported
Do legumes add nitrogen to the soil?
The fixing is real, and the destination is the plant rather than the ground. Soil gains when nodules, roots and eventually the whole plant decompose — so how much a soil ends up with depends on whether the plant stays in it.
- Mostly supported
Do sea turtles return to the exact beach where they were born?
They return to the right stretch of coast, reliably, after decades away — which is remarkable and well evidenced. "Exact" is the part that fails: the target behaves like a magnetic signature rather than a location, and that signature drifts along the coast, taking the nests with it.
- Mostly supported
Do salmon smell their way home?
For the last few kilometres, yes, and the experiment proving it is unusually clean. Across the ocean, no: a river’s scent does not reach the open Pacific at any usable concentration, and something else brings the fish to the right coastline.
- Mostly supported
Do birds navigate by the stars?
They do use the night sky, and the way they use it is better than memorising constellations: young birds learn which part of the sky stays still while the rest turns, and take north from that. A rotation, not a map.
- Mostly supported
Do Arctic terns fly from pole to pole?
It is the longest annual migration measured in any animal, and the "pole to pole" shorthand undersells it. The tracked route is not a straight line: it wanders, pauses in the mid-Atlantic for weeks, and comes out substantially longer than the distance between the two ends.
- Mostly supported
Do bombardier beetles really spray boiling liquid?
The temperature is right — about 100 °C, measured in 1969. The rest needs adjusting: it is a few microlitres in pulses of a few milliseconds, aimed at the point being bitten, and the beetle carries no hot chemicals at all.
- Mostly supported
Do baby birds babble like human babies?
The developmental resemblance is real and unusually specific — variable practice narrowing towards a model heard earlier, in both cases. What is not shared is anything to do with language, and the two lineages evolved the ability separately.
- Mostly supported
Do birds have accents?
Local song variants are real, sharply bounded in some species, and learned from local birds — which is the part of "accent" that transfers. What has not been shown is that a bird treats a foreign variant as the same thing said differently.
- Mostly supported
Can birds learn new songs throughout their lives?
Some do and many do not, and the difference is a real distinction in the field. A zebra finch learns once and sings the same song for life; a canary rebuilds its repertoire every year; a hummingbird at a lek keeps adjusting to match its neighbours.
- Mostly supported
Can elephants hear through their feet?
That elephants detect their own species’ calls arriving through the ground is demonstrated — played back seismically, with the airborne part below their hearing threshold, they respond. Exactly how the signal reaches the ear is not settled, and "through their feet" names a route that remains a proposal.
- Mostly supported
Can elephants communicate over kilometres?
The core is right and the distances get stretched. Elephant calls contain frequencies below human hearing, low sound genuinely does carry much further than high sound, and elephants respond to recordings of distant callers. How far this works in practice depends heavily on the weather, and quoted ranges are usually the best case reported as the normal one.
- Mostly supported
Do dolphins have names for each other?
Closer than you would expect, and not quite. A dolphin invents a whistle for itself as a calf and keeps it for life, others recognise the pattern with the voice stripped out, and dolphins copy each other’s whistles when separated. What has not been shown is one dolphin using another’s whistle to talk about it to a third.
- Mostly supported
Do animals teach their young?
A few species genuinely do, by a definition that requires the teacher to change its behaviour for the learner at a cost to itself. Meerkats grade the scorpions they hand pups. So do tandem-running ants — which should give anyone pause about what the word is capturing.
- Mostly supported
Are platypuses venomous?
Yes, with three conditions that change what it means: only adult males, mainly in the breeding season, and it is used on other male platypuses rather than on prey or predators.
- Mostly supported
Do platypuses sweat milk?
Close enough as shorthand — milk is secreted onto patches of skin rather than through teats — and it stops exactly where it gets interesting, which is what monotreme milk had to evolve to cope with as a result.
- Mostly supported
Can tardigrades survive in space?
Dried into the tun state first, and shielded from sunlight, they survived ten days of vacuum well. Under unfiltered solar ultraviolet nearly all of them died — and an active tardigrade in vacuum dies at once.
- Mostly supported
Can tigers purr?
Correct that tigers do not purr, and the reason usually given is the wrong one. It is the vocal folds rather than the bone. And tigers do make a warm greeting noise — the chuff — which anyone would call a purr if they had not been told otherwise.
- Mostly supported
Are tigers bigger than lions?
On average yes — and tiger size varies more between tiger populations than the tiger–lion gap does. A large Amur or Bengal tiger outweighs a lion comfortably. A Sumatran tiger is smaller than essentially any lion.
- Mostly supported
Is the largest living thing on Earth a fungus?
Broadly yes, with two honest qualifications. Single genetically identical Armillaria individuals really do span many hectares — one mapped in Michigan covers about fifteen — and by area they outrank any animal or tree. But the mass and age figures are extrapolations from growth rate rather than measurements, and whether a spread-out genet counts as "one organism" is partly a matter of definition.
- Mostly supported
Do dolphins really sleep with half their brain switched off?
The mechanism is real and the phrasing is wrong in a way that matters. One hemisphere enters slow-wave sleep — an active, structured state — while the other stays awake enough to keep the animal swimming and surfacing. Nothing switches off. The arrangement exists because breathing in a dolphin is voluntary, so total unconsciousness would be fatal.
- Mostly supported
Can crows recognise human faces?
Yes, in a specific and well-evidenced sense. Wild American crows learn a particular human face associated with being caught, remember it for years, and pass the association to birds that were never caught themselves. The "grudge" part is a human word for behaviour the experiments cannot see inside.
- Mostly supported
Do ants treat each other’s wounds?
The behaviour is real, precise and measurably effective — injured ants are carried home and their wounds are treated with antimicrobial secretions that substantially cut mortality. What the coverage adds is intention. Nothing in the research shows any ant deciding to help, and the ants that are left behind are left because they stop signalling, not because anyone judged them beyond saving.
- Mostly supported
Can a fish recognise a human face?
A fish can be trained to pick one human face out of dozens, which is a genuinely important result — it shows the task does not require the specialised brain structures usually invoked to explain it. But that is discriminating a photograph, not knowing who you are. No study has shown a fish recognising its owner.
- Exaggerated
Is a lichen two organisms — a fungus farming algae?
The composite idea is right and the count is not. Many lichens carry a second fungus in their outer layer as well as the algae, plus bacterial communities — and "farming" is a Victorian polemic against the discovery, not a description of it.
- Exaggerated
Did wolves change the rivers in Yellowstone?
Something real is underneath it, and the chain has been compressed into a single sentence that skips every step where the evidence runs out. The most testable link — that fear redistributed elk browsing — was tested at landscape scale and not found.
- Exaggerated
Do fungi do most of the decomposing?
It depends entirely on the material and the conditions. Fungi dominate where the substrate is tough and dry — wood especially. Bacteria dominate in wet, low-oxygen and nutrient-rich settings. Neither wins in general, and the animals shredding it all are a third thing again.
- Exaggerated
Do ants count their steps?
Stride length genuinely sets the distance an ant walks home — glue stilts to its legs and it overshoots, shorten them and it stops short. "Counting" is the stretch: nothing shows an ant representing a number, only that stride information feeds a distance estimate.
- Exaggerated
Do birds learn their songs from their fathers?
Sometimes, and it is not the rule. Many songbirds learn after leaving the nest, from the territorial neighbours they will spend their lives disputing boundaries with rather than from a parent — which turns out to make more sense than copying the father would.
- Exaggerated
Do birds sing at dawn to announce they survived the night?
There is something in it — dawn is when a territory that fell vacant overnight gets contested, so singing then is worth more. But it is one of at least three explanations, the best-tested of which is much more mundane: at dawn it is too dark to feed, so singing costs less.
- Exaggerated
Do parrots understand what they are saying?
One African grey, trained for decades by a specific social method, could answer questions about objects he had never seen — a real and demanding result, and one bird. A pet repeating a phrase is doing something else: reproducing a sound, which parrots are extraordinarily good at for reasons unrelated to meaning.
- Exaggerated
Do lyrebirds really imitate chainsaws and camera shutters?
Lyrebirds are extraordinary mimics and mechanical sounds are a very small part of what they copy. The famous clips are largely of captive birds; wild lyrebirds overwhelmingly imitate other birds — and the most remarkable thing they do is not a machine at all.
- Exaggerated
Can fish feel you tapping on the glass?
They certainly detect it — a tap puts energy into the glass and the water, and a fish has two systems that read it. What has been stretched is everything after that. Nothing measures what a tap is like from inside a fish, and the gunshot comparison is invented rather than measured.
- Exaggerated
Do fungi have a language of 50 words?
Fungal mycelium really does produce electrical spikes, and that has been recorded since the 1990s. The vocabulary came from an analyst deciding how long a gap ends a word, and no fungus was ever shown to respond to one.
- Exaggerated
Is there really an immortal jellyfish?
The reversal is real and the immortality is a translation error. Turritopsis medusae under stress can settle and turn back into polyps, escaping death by ageing. They remain entirely edible, and are eaten constantly. "Biologically immortal" describes senescence, not survival.
- Exaggerated
Do penguins mate for life?
Some species usually re-pair; others usually do not, including both of the ones people picture. Most king penguin pairs do not re-form — and the reason is the breeding schedule rather than fickleness.
- Exaggerated
Does a fungus turn cicadas into zombies?
The abdomen really is replaced by a plug of spores while the animal flies around, and infected males really do give the female mating signal. What has never been shown is that the fungus controls anything, or that the detected drugs do anything.
- Exaggerated
Do lions sleep for twenty hours a day?
The figure records *inactivity*, which includes resting, grooming, socialising and lying alert. Nobody has measured sleep in a wild lion, because that needs electrodes on one.
- Exaggerated
Is honey the only food that never spoils?
Honey keeps remarkably well, for reasons that are well understood: it is dry enough that most microbes cannot grow, mildly acidic, and generates hydrogen peroxide as it is diluted. But "never" overstates it — honey that takes up moisture will ferment — and it is not unique, since salt, sugar and dried grains keep on the same principle.
- Exaggerated
Are slime moulds intelligent?
The experiments are real and the word is doing too much. Physarum finds the short path through a maze because tubes carrying more flow thicken and the rest are reabsorbed — no representation of the maze, no comparison, no choice. It genuinely does habituate, which is real learning of the simplest kind. Neither result needs, or supports, intelligence.
- Exaggerated
Do all plants need bees?
Around 88% of flowering plant species depend on animals — but the animals are tens of thousands of species of bee, fly, beetle, moth, butterfly, bird and bat. And the crops supplying most human calories are wind-pollinated: wheat, rice and maize need no animal at all. The finding underneath is more alarming, not less: the pollination that matters is largely done by wild insects nobody counts.
- Exaggerated
Do elephants mourn their dead?
The behaviour is real and repeatedly documented: elephants approach, touch and investigate dying and dead elephants, including unrelated ones, and return to remains. Whether they experience grief is not something any study so far could establish or rule out.
- Exaggerated
Do ravens hold grudges?
The memory is real and unusually long. The grudge is not something the experiments can see. Ravens recognise former companions by voice after up to three years, and their response differs depending on whether that individual was an ally or a rival — which is a statement about memory, not about intent to retaliate.
Not settled · 11
Where the evidence has not landed yet
Early results, and live disagreements between specialists. Neither is a failure to answer: an honest "we do not know yet" is a destination, and rounding it up to something tidier is how confident nonsense gets made.
Do the barnacles on a whale do it any harm?
Nobody really knows, and the confidence of the textbook answer is the problem. Barnacles add drag and mass, and whether that costs a whale anything measurable has not been established for most species — "commensal" here means no effect has been looked for.
Where you may have met it: school biology and revision guidesRead on- Early evidence
Do elephants call each other by name?
The evidence is better than most readers were told and thinner than the headlines implied. A model could predict which elephant a rumble was aimed at, and — the part that matters — playing those calls back made the addressed elephant respond more strongly. One study, seventeen playback subjects, no replication yet.
- Early evidence
Do sperm whales have a language?
What was found is structure — the clicks vary along more dimensions than anyone had catalogued, and the variation tracks conversational context. No meaning has been demonstrated, and the paper does not claim any.
- Early evidence
Do octopuses dream?
Octopuses have a sleep stage with the behavioural and neural hallmarks of REM sleep, including rapid skin-colour changes and wake-like brain activity. Whether anything is experienced during it is unknown, and no available method could find out.
- Disputed
Do city birds sing higher because of traffic noise?
They do sing higher in noisier places. Whether that is an adaptation to escape traffic noise is genuinely contested — the shifts are far too small to help, and the leading alternative is that the birds are simply singing louder, which raises pitch as a side effect.
- Disputed
Do mother trees feed their own seedlings through the fungal network?
Carbon does move between trees through fungal connections — that much is measured. That a large tree recognises its own seedlings and provisions them is not established, and a 2023 review found the claim being cited far more confidently than the underlying data support.
- Disputed
Can gorillas understand sign language?
Apes do learn hundreds of signs and use them deliberately. The claim that they combine them grammatically did not survive frame-by-frame analysis — and in the best-known gorilla case the records were never released, so it cannot be checked either way.
- Disputed
Can plants learn and remember?
Two different claims. Habituation in Mimosa — the simplest form of learning, found in organisms with no nervous system — has support. Associative learning in pea plants, the result that made the case for something cognitive, failed to replicate.
- Disputed
Do oak trees produce huge acorn crops to overwhelm the squirrels?
Predator satiation is a real hypothesis with real support, and it is not settled and involves no tree deciding anything. Where seed predators are resident, big crops do get more seed through; where they are mobile, it weakens. And a competing explanation has its own evidence: wind-pollinated trees flowering together get far more pollen onto stigmas.
- Disputed
Do trees talk to each other through fungal networks?
Fungi really do connect plant roots, and carbon really does move between trees below ground. The elaborated story — that networks are ubiquitous, that transfers matter to the recipient, and that mature trees preferentially feed their kin — was examined by two independent reviews in 2023 and found unsupported by the primary literature.
- Disputed
Did wolves change the rivers of Yellowstone?
Real changes happened and wolves may have contributed. Whether they caused them is genuinely disputed: the specific prediction the theory makes was tested at landscape scale and did not hold, and the same period brought a severe drought, a bison irruption, recovering grizzlies and a large human elk hunt.
Widely repeated, and wrong
Claims with no good evidence behind them, and claims whose words are defensible while the impression they leave is not. Several of these have been in circulation for a century.
Are apex predators keystone species?
Sometimes, and it has to be shown rather than assumed. Keystone means an effect out of proportion to abundance — so a top predator that matters exactly as much as its numbers suggest is not one, and being at the top does not settle it.
Where you may have met it: conservation campaign material- Misleading
Are earthworms always good for soil?
True of a garden. In northern forests that have had no earthworms since the ice age, the same species doing the same thing strip the leaf layer the understorey depends on. The animal has not changed; what was there before has.
- Misleading
Does bleaching mean the coral is dead?
Not yet. Bleaching is the loss of the photosynthetic partners that supply most of the coral’s energy. The animal is alive and starving, and can recover if the heat passes — which is a smaller reassurance than it sounds.
- Misleading
Are non-native species invasive?
Three different words are being used as one. Non-native describes origin, established means it persists, invasive means it spreads and causes harm — and most non-native species never reach the third.
- Misleading
Are tropical mosquitoes now established in Britain?
On 3 September 2026 UK authorities confirmed Aedes aegypti breeding in Britain for the first time — and stated that the species is not established, that the detection was accidental importation, and that the public-health risk was very low. Breeding is not establishment, and establishment is not transmission.
- Misleading
Does it take 500 years to make an inch of soil?
There is no single rate. Soil formation depends on parent material, climate, organisms, slope and time, and measured rates span orders of magnitude — and the figure is usually quoted with no source, soil type or process attached.
- Misleading
Do pigeons have magnets in their heads?
The specific version is wrong: the iron-rich cells in pigeon beaks that were long presented as magnetoreceptors turned out, on close examination, to be immune cells. The evidence that actually holds up for pigeon navigation is about smell over unfamiliar ground and learned routes over familiar ground.
- Misleading
Do birds migrate because it gets cold?
They leave because the food goes, not because the air is cold — plenty of small birds sit out northern winters perfectly well. And the departure is timed by day length, which is why birds often leave while the weather is still mild.
- Misleading
Is migration purely instinctive?
What is inherited is a direction and roughly how long to fly — a rule, not a route. Displace a first-year bird and it flies that rule into the wrong continent, while an adult beside it corrects. And in some species the route is not inherited at all, but learned from older birds.
- Misleading
Do bar-headed geese fly over Mount Everest?
When the birds were finally tracked they flew mostly at night, followed the terrain, used passes, and spent very little time above 6,000 metres. The physiology is genuinely exceptional — the story attached to it is not what the tags show.
- Misleading
Do animals adapt to their environment during their lives?
An individual cannot adapt. It can acclimatise — remodel itself over days or weeks, reversibly, up to a fixed ceiling. Adaptation happens to populations across generations. The two are routinely confused, and they predict different outcomes for a species.
- Misleading
Why are deep-sea animals not crushed by the pressure?
Nothing down there is being crushed. Water barely compresses, so a body made of water is fine at any depth. Pressure’s real effect is on molecules — it unfolds proteins and stiffens membranes — and hadal animals are notable for having less rigid structure, not more.
- Misleading
Do bright colours mean an animal is poisonous?
Warning coloration is real, and the inference is not reliable in either direction. Plenty of conspicuous animals are harmless mimics borrowing somebody else’s reputation, plenty of highly toxic animals are drab — and “bright” means bright to whichever eyes are looking, which are usually not ours.
- Misleading
Do butterfly eyespots scare birds by looking like owl eyes?
The display genuinely works — butterflies with eyespots painted out were attacked far more. But when researchers varied eye-likeness and conspicuousness separately, equally conspicuous bars and squares protected prey just as well as circles.
- Misleading
Do lizards drop their tails whenever they are frightened, and does the tail grow back?
Both halves are wrong in the same direction. Shedding is a graded decision, not a reflex — the threshold shifts with how bad the situation is and what the tail is worth. And what grows back is a rod of cartilage that cannot be shed again.
- Misleading
Do opossums choose to play dead?
The behaviour is real and it works — but the evidence does not support it being a choice. An opossum in this state cannot readily be roused, which is not what a monitored performance looks like, and the response includes physiological changes it does not control.
- Misleading
Does the zombie-ant fungus take over the ant’s brain?
The behaviour is real and precisely as strange as advertised. The brain part is not. When infected ants were reconstructed in three dimensions, fungal cells filled the body and wrapped individual muscle fibres — and the brain was essentially free of them.
- Misleading
Are host birds fooled by cuckoo eggs?
Hosts reject eggs in proportion to mismatch, reject more readily where cuckoos are common, and become suspicious of an egg they would otherwise accept if they have just seen one. Accepting a good match is often the decision that pays, because ejecting risks destroying their own.
- Misleading
Are birds born knowing their songs?
Something is inherited and it is not the song. A songbird raised where it can hear no other bird still sings — and produces something no wild bird would recognise. The rough envelope comes free; the pattern has to be learned from an adult.
- Misleading
Do birds sing because they are happy?
What song is for has been tested, and the answers are territory and mating. Whether a singing bird feels anything is a separate question that nobody can currently answer — and saying so is not the same as saying it feels nothing.
- Misleading
Do snakes see heat?
The organ is a thermometer, not an eye: a membrane suspended behind a hole, warmed slightly by radiation. Heat and light do meet in one map in the snake’s brain, which is the genuinely remarkable part — but nothing shows the animal experiences that as vision, and the thermal-camera image is our picture, not its.
- Misleading
Can birds see the Earth’s magnetic field?
A bird’s magnetic compass does appear to run through its eyes and to need light, which is genuinely strange and well supported. That this produces something the bird sees is not a finding — it is an illustration of a model, and no experiment has tested it or could currently distinguish it from the alternative.
- Misleading
When a tree dies, does all its carbon go straight back into the air?
Most of it does return, but over decades rather than at once, and not all of it. A fraction ends up as soil carbon that can persist for centuries — and it is mostly the remains of the microbes that did the eating, not the parts of the wood nothing could digest.
- Misleading
How much carbon dioxide does a tree absorb in a year?
There is no general figure. Uptake varies by more than tenfold with species, size, age and site, and the numbers in circulation are averages over distributions in which a small minority of large trees accounts for most of the total.
- Misleading
What is the oldest tree in the world?
It depends entirely on what is being counted. The oldest dated single stem is a bristlecone pine of over 4,800 years. The 80,000-year figure refers to an aspen clone — an estimate of how long a lineage has been spreading, not the age of any trunk in it.
- Misleading
Do female spiders eat the male after mating?
It happens, in a minority of species, and it is not what usually ends a spider mating. In most of the 52,000 known spiders the male leaves and may mate again. And in the best-known case that does fit the story — the redback — the male somersaults into the female’s fangs himself, which makes it his tactic rather than her ambush.
- Misleading
Do orcas live to 100?
A very old female in the best-studied population may approach it; the average is nothing like it, and males average around thirty. One number cannot describe a species whose two sexes differ by twenty years and whose populations differ again.
- Misleading
Do squirrels hibernate?
It depends entirely which squirrel. Tree squirrels do not hibernate — they stay active all winter and the caches are what they live on. Ground squirrels are among the deepest hibernators known, and the arctic ground squirrel holds a body temperature below freezing. One word covering both makes the question unanswerable.
- Misleading
Can a starfish grow back from any piece?
In most starfish an arm alone dies. Regrowing a whole animal from a fragment needs part of the central disc, and only a small number of species — Linckia most famously — manage it from an arm by itself. The reputation of the group comes from its exceptions.
- Misleading
Are snakes deaf?
No. Snakes have no eardrum and no external ear, which is not the same as no hearing. They detect airborne sound and are far more sensitive to low-frequency vibration through the ground — a hearing profile, not an absent sense.
- Misleading
Is ambergris whale vomit?
Wrong end. It forms in the rectum, not the stomach, as a concretion around indigestible squid beaks — and it leaves the way that implies, or is released when a blocked whale dies.
- Misleading
Do plants scream when you cut them?
Stressed plants do emit ultrasonic clicks — a few dozen an hour, at frequencies no human can hear, produced by water columns snapping under tension. Nothing indicates they are produced for a listener, and no listener has been identified.
- Misleading
Does the human liver grow back?
It restores its mass, not its shape. Remove a lobe and the lobe does not return; the remaining tissue enlarges until the total is back to what it was, then stops — with remarkable precision.
- Misleading
Do platypuses glow under ultraviolet light?
The fur does fluoresce under an ultraviolet lamp — which is not glowing in the dark, and needs the lamp. Whether it means anything is entirely unknown, and it has since turned up in a lot of unrelated mammals.
- Misleading
Can tardigrades survive anything?
An active tardigrade dies at around 37°C — roughly the temperature of a warm bath. Everything it is famous for belongs to the desiccated tun state, and even there the limits are finite and get worse with time.
- Misleading
Do male lions hunt, or do the females do all the work?
Males hunt regularly and successfully — in cover, at night, favouring larger prey. The claim describes where and when researchers could see, not what lions do.
- Misleading
Do tigers have striped skin, not just striped fur?
The pattern really is a property of the skin — it is drawn there in the embryo before the animal has any hair. The pigment you see is in the hair. Whether a shaved tiger looks striped is a third question, and we could not find anyone who has actually measured it.
- Misleading
Are tigers completely solitary?
They travel alone, which is what the word is doing. They also live inside a structured neighbourhood they maintain by continuous scent marking, and most tigresses settle next to their mothers — sometimes on ground their mother gives up for them.
- Misleading
Is honey bee vomit?
The words are defensible and the impression is wrong. Nectar is carried in a crop — a storage pouch that is not the bee’s digestive stomach — and comes back up through the same route it went down. It is also chemically changed on the way: enzymes split the sugars, and the water content is driven from around 70% to under 20%. Regurgitated, yes. Digested and brought back up, no.
- Misleading
Do bees calculate the perfect hexagon?
The comb really is close to a regular hexagonal array, and the efficiency is real. The mechanism is what is wrong. Bees do not measure angles: they work roughly circular cells in wax kept near 40°C, and the shared walls between neighbours relax into hexagonal junctions as the warm wax settles. The geometry emerges from physics acting on a material.
- Misleading
Do plants call for help when they are attacked?
Everything in the mechanism is real and the word "calls" is not. A damaged plant emits volatile compounds, the blend differs depending on what is eating it, and parasitoid wasps orient towards it and find the caterpillars. Nobody is summoning anybody: injury has a chemical signature, and wasps that can smell it eat better than wasps that cannot.
- Misleading
Is pollen plant sperm?
A pollen grain contains sperm cells; it is not one. It is the male gametophyte — a complete, if tiny, organism of two or three cells with its own wall — which lands on a stigma and grows a tube down into the flower to deliver two sperm cells. The analogy hides the most interesting part, which is that the stigma inspects the grain and can refuse it.
- Misleading
Do birds just know where to migrate?
A first-year bird inherits a direction and roughly how long to fly it — which is not the same as knowing where to go. Displace a juvenile a few hundred kilometres and it flies the same heading into the wrong country; displace an adult and it corrects. Knowing where you are is learned by making the journey. And the magnetic compass is not a GPS: it gives direction, not position.
- Misleading
Is camouflage a kind of mimicry?
No, and the distinction is what stops the word covering every resemblance in nature. Mimicry needs three parties: a model, a mimic, and a receiver whose behaviour changes because it is deceived. A stick insect is not being treated as a stick and acted on accordingly — it is not being detected at all, which is camouflage.
- Misleading
Does a monarch butterfly fly all the way to Mexico and back?
No individual makes the round trip. The autumn generation flies south and overwinters in Mexico, starts back north in spring and dies on the way; two or three further generations complete it. The butterflies arriving in Canada are the great-grandchildren of the ones that left, which makes the navigation harder to explain.
- Misleading
Do crows hold funerals for their dead?
Crows really do gather and shout around a dead crow, and it has been tested with proper controls. What the experiment found was danger learning: the birds avoided the place afterwards and scolded the person who held the body for weeks. Nothing in the design could detect mourning.
- Not supported
Does symbiosis mean both species benefit?
No. Symbiosis means different species living closely together, and that is all it means. Parasitism is a symbiosis. So is a tapeworm in a gut. The narrowing to "both benefit" is popular usage, not the technical one.
- Not supported
Do ecosystems reach a natural balance?
Disturbed systems sometimes return to something like what they were, sometimes settle into a different arrangement and stay there, and sometimes keep changing. Which one happens is a question with a different answer in different places.
- Not supported
Is a keystone species the most abundant one in its ecosystem?
Close to the reverse. Keystone means an effect out of proportion to abundance, so a dominant species that matters exactly as much as its numbers predict is not one. The word for the abundant, structure-forming species is foundation species.
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Is humus a stable substance that lasts for centuries?
The evidence for distinct stable humic molecules came largely from extracting soil with strong alkali. Methods that examine organic matter in place find a continuum of ordinary fragments getting smaller — and carbon that lasts does so because decomposers cannot reach it.
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Do monarch butterflies remember the route to Mexico?
They cannot be remembering it. The butterflies arriving in Mexico are three or four generations removed from the ones that left, so no individual in the chain has made the journey before. What gets them there is a sun compass, an inherited direction, and a switch thrown by cold weather.
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Do camels store water in their humps?
The hump is fat. What actually saves a camel water is stranger and better: a dehydrated camel lets its own body temperature swing about six degrees across the day rather than sweating to hold it steady, and radiates the stored heat away at night.
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Is hibernation just a long sleep?
Not sleep, and not continuous. Sleep barely lowers metabolic rate; hibernation lowers it by up to ninety-five per cent, further than the cooling alone can explain. And hibernators wake repeatedly through the winter, at enormous cost, for reasons that are still not settled.
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Do zebra stripes camouflage them or confuse predators?
Modelled through lion and hyena vision, the stripes blur into uniform grey beyond about fifty metres in daylight — and much closer at dusk, when those predators hunt. A lion near enough to resolve stripes has already found the zebra.
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Do constricting snakes suffocate their prey?
It was the standard explanation for a century and had never been measured. When somebody finally instrumented the prey, blood pressure collapsed and circulation arrested within seconds — far faster than suffocation, and by an entirely different route.
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Do cheetahs give up a chase because they overheat?
When temperature loggers were implanted in free-living cheetahs, body temperature rose only modestly during hunts and unsuccessful hunts were no hotter. The substantial rise came *after* a successful kill, which is probably why the original inference looked so convincing.
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Do porcupines shoot their quills?
No porcupine has any mechanism for propelling a quill. The real explanation is better: the quills are barely attached to the porcupine and grip hard in whatever they enter, so contact alone transfers them.
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Do predators catch most of the prey they go after?
Where hunts have actually been counted, most attempts fail — usually well over half, sometimes far more. A hunt is a sequence of stages, each of which can go wrong on its own.
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Are hyenas scavengers that steal from lions?
The theft mostly runs the other way. Years of observation, including at night, found spotted hyenas hunting most of what they eat and lions frequently appropriating their kills. The reputation comes from watching, in daylight, an animal that hunts in the dark.
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Is a starling murmuration led by one bird?
Nothing in the measurements requires a leader. Each bird tracks about seven neighbours, correlations stretch across the whole flock so a turn anywhere is felt everywhere, and in models a small minority nobody can pick out is enough to steer a large group.
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Do only male birds sing?
No. Female song has been recorded in around seventy per cent of the songbird species surveyed worldwide, and the common ancestor of songbirds almost certainly sang regardless of sex. The idea came from studying birds in the one part of the world where male-only song happens to be common.
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Is birdsong a language?
No. Birdsong is learned, culturally transmitted and structurally complex — three properties language has — and there is no evidence that any part of a song refers to anything. The best candidate for something language-like in birds is not song at all, but a pair of calls that combine in a fixed order.
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Do birds teach their young to sing?
Young birds learn from adults and there is no evidence that any adult is teaching. The learner does the work: memorising, practising and correcting itself against what it stored. That is copying, not instruction — and the two have a formal difference that matters.
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Can a mantis shrimp see more colours than we can?
The opposite, as far as anyone has been able to test it. Asked to tell two colours apart, mantis shrimps needed the wavelengths much further apart than a human does — they discriminate colour considerably worse than you do, despite having four times as many receptor classes.
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Can bees find their way on a cloudy day?
A patch of blue sky is enough. Scattered sunlight is polarised in a pattern fixed by where the sun is, insects read that pattern, and it still gives the sun’s position when the sun itself is hidden. Rotate a polarising filter over an ant by forty degrees and it walks off forty degrees wrong.
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Is dead wood in a forest waste that ought to be tidied away?
A fallen trunk is one of the most densely occupied objects in a wood, and the species using it are largely different from those anywhere else in the forest. The disease worry applies to specific pathogens in specific situations, not to deadwood in general.
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Has AI translated what whales are saying?
No. The analysis behind the headlines is real and careful, and it found more structure in sperm whale clicks than anyone had catalogued. It identified no meanings, and no whale was tested. Translation needs pairs of things that already mean the same in both systems, and for animals no such pairs exist or can be made.
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Do old trees stop absorbing carbon?
The opposite, at the level of the tree. Repeat measurements of 673,046 trees across 403 species found that for most species, the bigger a tree gets the more mass it adds each year — some of the largest add as much in a year as a mid-sized tree contains.
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Is a tree made from the soil it grows in?
No. Roughly half the dry mass of wood is carbon that entered as gas through the leaves. The soil supplies about one per cent of a tree’s dry weight, as minerals — and this was demonstrated in the 1640s.
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Do a tree’s roots mirror its branches underground?
No, in both dimensions. About half a tree’s root mass sits in the top 30 centimetres of soil, and the system commonly spreads two to three times further than the branches.
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Is a hollow tree a dying tree?
No. The wood that rots out of the middle was already dead and was moving nothing. Hollow veteran trees are often centuries old, still growing, and among the richest habitats a woodland has.
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Did octopuses come from space?
No. The paper exists and was published in a peer-reviewed journal, and it was rejected almost universally by the biologists who read it. Octopus genomes sit exactly where they should on the molluscan tree, sharing ancestry with squid, cuttlefish and snails. Being strange is not evidence of foreign origin.
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Do snakes dislocate their jaws to swallow prey?
No. Nothing is dislocated, because nothing was joined in the first place — the two halves of a snake's lower jaw are separate bones held together at the front by an elastic ligament, and they simply spread apart.
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Do snakes chase people?
No snake hunts people, and none is known to pursue them. The experience is real: a frightened snake heading for cover will come straight at you if you are standing between it and the cover.
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Do penguins have knees?
They have knees. The thigh bone is short and held roughly horizontally inside the body wall, so the knee sits under the feathers — and the backward-bending joint you can see is the ankle.
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Do all penguins live in Antarctica?
Two species out of roughly eighteen breed exclusively in Antarctica. The rest live around the Southern Hemisphere, and one breeds on the equator in the Galápagos. No penguin has ever met a polar bear.
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Are gorillas ten times stronger than humans?
Nobody has ever measured it. The multipliers descend from 1920s dynamometer trials on captive apes whose motivation could not be controlled — and the one rigorous measurement, at the level of muscle fibres in chimpanzees, found about 1.35 times.
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Did humans evolve from gorillas?
No. Gorillas are a cousin lineage that has been evolving for exactly as long as we have, and chimpanzees are closer to us than gorillas are. We did not pass through a knuckle-walking stage either.
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Can a sperm whale kill you with its clicks?
The decibel figure is real and is being quoted on the wrong scale. Underwater decibels use a different reference from the airborne ones people know; converting properly removes about 62 units. There is no documented case of anyone being harmed.
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Do plants feel pain?
Plants detect damage quickly and specifically, and signal it through their own tissues. Detecting is not feeling: there are no pain receptors, no neurons and nothing that could constitute an experience.
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Are tardigrades immortal, and can they survive dried out for a century?
The century figure traces to one report of a leg moving in a museum specimen, which was not revival. Tested against moss of documented age, survival runs to years and declines steeply.
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Are lions the king of the jungle?
Lions do not live in jungle. No male rules a pride — the females are the permanent members and the males are visitors who hold it for a few years. And lions lose carcasses to hyenas as well as taking them.
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Are white tigers a separate species, or a rare kind of tiger?
No. A white tiger is a Bengal tiger with two copies of one recessive change in a single pigment gene. It is not a species, not a subspecies, not a snow adaptation and not an albino — and no white tiger belongs to any wild conservation programme.
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Is lichen killing my tree?
No. A lichen has no roots and no connection into the tree at all — it sits on the bark and absorbs water and minerals from rain and air. The correlation is real but the causation runs the other way: a tree with a thinning canopy lets more light through, and more light is what lichens want.
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Are poisonous mushrooms brightly coloured?
No, and the belief is dangerous in a specific way. The species responsible for most fatal poisonings is a plain greenish-white mushroom that reportedly tastes pleasant. The vivid red-and-white fly agaric of the illustrations is rarely fatal. Colour, smell, taste and whether animals eat it have no reliable relationship to toxicity.
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Do bears actually hibernate?
They do, and the old objection measured the wrong thing. A denning black bear runs at roughly a quarter of its normal metabolic rate for months. Body temperature falls only a few degrees because a body that size cannot cool like a ground squirrel — not because the response is shallow.
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Are orchids parasites?
No. About seven in ten orchids grow on other plants and take nothing from them: no root penetrates the host and no connection to its plumbing exists. They use a branch as a perch, collect water through a spongy root covering, and photosynthesise for a living. The word for that is epiphyte.
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Can ants recognise themselves in a mirror?
No. The claim comes from a single small study published in a venue with an unclear review process, using subjective scoring, never independently replicated. There is no accepted evidence of mirror self-recognition in any insect.
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Is there such a thing as an alpha wolf?
No. Wild wolf packs are families — a breeding pair and their offspring — and the parents lead because they are the parents. The alpha model was derived from unrelated captive wolves confined together, and the researcher who popularised it has spent decades asking for it to be dropped.
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Can a shark smell a single drop of blood from miles away?
No, and the claim fails on physics before it fails on biology. Shark olfaction is good but not extraordinary among fishes, and odour reaches a shark only as fast as the current carries it — a shark upstream of blood detects nothing at all, however close it is.
What our verdicts mean
A verdict is a reading aid, not a score. “Disputed” and “early evidence” are legitimate destinations — we do not round a nuanced result up to something tidier.
- Supported
- Good evidence backs this, and specialists broadly agree.
- Mostly supported
- The core is right; the usual phrasing overstates part of it.
- Early evidence
- Real findings exist, but too few or too new to settle the question.
- Disputed
- Specialists actively disagree, and the disagreement is substantive.
- Exaggerated
- Something true sits underneath, stretched well past what was shown.
- Misleading
- The words are defensible; the impression they create is not.
- Not supported
- No good evidence supports this, or the evidence points the other way.