Devious deceivers, identity thieves, double-crossers, con artists, impostors, cheats, hostage-takers and wolves in sheep’s clothing – here is Stuart Blackman's pick of the animals that trick, exploit and outwit others in the most cunning ways…
10 cruellest tricksters in the animal kingdom
Untrue blues
Many members of the blue family of butterflies maintain a close working relationship with ants, providing sweet honeydew in return for protection from predators. But some species have turned traitor on their guardians.
Young alcon blue caterpillars look, smell and even sound remarkably like ant grubs. So good is the disguise that the ants carry the live caterpillars back to their nest in mistake for one of their own, at which point the caterpillars abandon their vegetarian diet and start munching their way through the ants’ brood.
To an ant, the caterpillar appears even more like an ant-grub-like than does an actual ant grub. Should the colony need to relocate, they transport the caterpillars first and, when food is short, they will sacrifice their own larvae and feed them to their guests.
Taken to the cleaners
Coral reef cleaning-stations are places of sanctuary where hostilities between predators and prey are temporarily suspended. Staffed by little striped fish called bluestreak cleaner wrasse, they are the destination of larger species in need of a makeover.
The wrasses’ distinctive colours and movements elicit a trance-like state in their clients, who open their mouths and gill slits and allow the cleaners to remove parasites and dead skin and tissue from their most intimate nooks and crannies.
It’s an arrangement of mutual benefit to cleaner and client. But it is also open to exploitation by less honourable interests. False cleanerfish belong to an unrelated family of fishes called the blennies, and yet they look and move remarkably like the wrasse.
They too can lull passing fish into a relaxed stupor, but they do so in order to bite rather than pamper, and the victim only realises its error when the imposter darts in to take a chunk out of one of its fins.
Paternity test
The dunnock is an unassuming little-brown-job of a bird, but there is nothing conservative about its sex life. This familiar inhabitant of European gardens scoffs at the notion of the nuclear family. While some nests are tended by a conventional male and female pair, others are occupied by a foursome of two males and two females, and the most common arrangement consists of a single female and up to three males.
This variation is driven, at least in part, by the fact that females mate repeatedly with several males, which generates uncertainty over who exactly has fathered a brood. Indeed, a single nest will often contain chicks sired by multiple males.
Amidst this confusion, any males that think they may have a genetic stake in a brood will be inclined to help raise it. The female’s sexual smoke and mirrors transforms male suspicion into a healthy supply of insects for her offspring.
Rotten trick
Many animals, from snakes to frogs to possums, play dead as a last-ditch defence against predators. But in the depths of Lake Malawi, southern Africa, there’s a predator that puts the trick to more sinister use. Livingston’s cichlid hunts by laying motionless on its side on the lake’s sandy bottom. Its blotchy colours add to the illusion that it is a dead fish in the early stages of decay. All it has to do is wait for a smaller scavenger to come and investigate, at which point it comes back to life in an instant to gulp down its victim.
Fake it till you make it
Male fiddler crabs are masters of the sleight of hand – in more ways than one. These lopsided crustaceans are famous for the unequal size of their claws. They have one small one (which may be either the right or the left), which they use for feeding, and one very big one that they wave around in territorial displays and wield in fights with rivals. The bigger the claw, the better they can defend their patch of the beach
A male that loses its larger claw in a fight is unable to compete at all. It can grow a new one in a few months, but the replacement is never quite as good as the original. Which is where the trickery comes in. Replacement claws are about size rather than substance. They make for an impressive display – good enough to scare off many rivals with smaller claws – even though they contain little in the way of muscle. The illusion can only be broken by those brave enough to engage in mortal combat.
Completely cuckoo
Few, if any, animals are as deceitful – and on so many levels - as the Eurasian cuckoo.
Cuculus canorus is the classic brood parasite, duping warblers, pipits, dunnocks and other small birds into raising its chicks for it.
The deceit starts with the barred plumage of the adult bird, which bears a striking resemblance to that of a sparrowhawk. It is thought that, by posing as a predator, the cuckoo frightens birds away from their nests, giving it the opportunity to dart in and deposit its single parasitic egg.
Second, to reduce the risk of being rumbled, female cuckoos target hosts that lay eggs similar to their own. Strangely, cuckoos parasitize a wide range of host species, whose eggs vary dramatically in appearance. And cuckoo eggs, too, are extremely variable between individuals. This means that each female cuckoo specialises in parasitizing a different subset of all the potential host species.
Finally, once the cuckoo chick has hatched and violently ejected the host’s own young from the nest, it must fool the foster parents into thinking they still have an entire brood to feed – because a growing cuckoo needs a lot of food. It does this by producing calls that sound like a whole nest-full of chicks begging simultaneously.
Due to these deceitful moves we have named the cuckoo one of the laziest animals in the world
Pollinator prison
Plants, too, can be devious. On the islands of the Mediterranean, the dead horse arum is hard to miss and even harder to stomach. Its flower - a grotesque purple fleshy structure that sprouts what look like mammalian bristles - emits a stench of rotting carrion. Blowflies, attracted by the promise of a meat feast and a place to lay eggs, find it irresistible.
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Only once the insects have crawled into the flower’s depths do they discover they’ve been conned. And trapped - by downward-pointing spines that prevent escape.
Taking flies prisoner is the dead horse arum’s way of getting the most out of its pollinators. Each bloom lasts just a couple of days. For the first day, only the female parts of the flower are developed, ready to receive any pollen brought by the insects from elsewhere. To prevent self-pollination, the male parts don’t produce their own pollen until the second day, by which time the female parts are no longer receptive.
By imprisoning the flies overnight, the plant ensures that flies transfer pollen both to and from the plant. Only then does it grant its captives their freedom – at least until they stumble into the next dead horse arum flower.
Snakes alive!
If scaring the life out of something that is trying to eat you counts as cruel, then the caterpillar of the spicebush swallowtail butterfly deserves a place on the list. Because it certainly pulls off a remarkable trick.
Many butterflies and moths – both adults and larvae - deter predators with patterns on their bodies that look like the eyes of a much larger animal. The eyespots of caterpillars are often displayed on the swollen front end of the body, which gives them a snake-like appearance. But the spicebush swallowtail completes the illusion with an exquisite detail. When threatened, it rears up and inflates a bright red, forked structure on its head – called an osmeterium - that looks just like a flickering serpentine tongue.
If scaring the life out of something that is trying to eat you counts as cruel, then the caterpillar of the spicebush swallowtail butterfly deserves a place on the list. Because it certainly pulls off a remarkable trick.
Many butterflies and moths – both adults and larvae - deter predators with patterns on their bodies that look like the eyes of a much larger animal. The eyespots of caterpillars are often displayed on the swollen front end of the body, which gives them a snake-like appearance. But the spicebush swallowtail completes the illusion with an exquisite detail. When threatened, it rears up and inflates a bright red, forked structure on its head – called an osmeterium - that looks just like a flickering serpentine tongue.
Two-faced cuttlefish
Cephalopods are famed for their fierce intelligence and their remarkable colour-changing abilities. It’s a useful combination for those of a devious disposition, and cuttlefish don’t disappoint in that regard.
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Male mourning cuttlefish of Australia woo females with mesmerising displays of moving stripes along their flanks. The trouble is that males compete vigorously for female attention and rival males will drive courting couples apart violently if they spot them.
However, some males have come up with a cunning way to impress females without being rumbled. By positioning himself between the female and a male spectator, a courting male can signal different messages to each party simultaneously. On one side of his body, he mesmerises his mate with the stripe display, while on the other side, he mimics the colours of a female cuttlefish to avoid confrontation with his rival, who has no idea he’s been duped.
Cephalopods are famed for their fierce intelligence and their remarkable colour-changing abilities. It’s a useful combination for those of a devious disposition, and cuttlefish don’t disappoint in that regard.
- 10 cuttlefish facts you may not know
- "We were amazed to observe a cuttlefish waving back" – video experiment stuns scientists
- Watch incredible footage of a tiny flamboyant cuttlefish hatching from its egg. Is this the cutest baby fish in the ocean? It's certainly the prettiest
Male mourning cuttlefish of Australia woo females with mesmerising displays of moving stripes along their flanks. The trouble is that males compete vigorously for female attention and rival males will drive courting couples apart violently if they spot them.
However, some males have come up with a cunning way to impress females without being rumbled. By positioning himself between the female and a male spectator, a courting male can signal different messages to each party simultaneously.
On one side of his body, he mesmerises his mate with the stripe display, while on the other side, he mimics the colours of a female cuttlefish to avoid confrontation with his rival, who has no idea he’s been duped.
The bird that cried wolf
The trick played by the fork-tailed drongo is a cheap one, but it’s highly effective. This common insectivorous bird of Sub-Saharan Africa is a skilled mimic of the calls made by other birds and mammals such as meerkats. It often forages alongside them and will issue alarm calls that warn its fellow travellers of approaching danger.
Sometimes, though, drongos put their mimetic abilities to more devious use, raising the alarm when no threat is present and then stealing any food that is abandoned during the rush for cover.
The drongo’s sophisticated strategy of mixing honest and dishonest alarm calls depending on the situation might give the impression that the birds have an understanding of the state of mind of other animals. But the scientists who study them argue that it’s more likely that the behaviour is learned through simpler processes such as trial and error.
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