
Giraffes have blue tongues

Forget pink tongues: a giraffe’s tongue is blue-black in color. It’s likely that the color is down to the need to protect the tongue from the strong African sun. After all, giraffes spend hours every day browsing through the upper branches of acacia trees, feeding off leaves and twigs. Their tongue and lips are also tough and thick to protect them against the acacia’s thorns.
Some mammals lay eggs

It isn’t only birds, reptiles, amphibians, fish and insects that lay eggs. Some mammals do too! Perhaps you know about the duck-billed platypus but four types of echidna – the western long-beaked, the eastern long-beaked, the short-beaked, and Sir David’s long-beaked – also lay eggs. All five of these mammal species are found only in Australia or New Guinea.
Some birds can fly backwards

Flying backwards is a real challenge. Although some species of birds, notably egrets, herons, flycatchers and warblers, can flutter backwards briefly as a defensive strategy, only hummingbirds have mastered the skill. This is thanks to the design of their wings, which also even allows them to fly upside down.
Slugs have four “noses”

Actually, this isn’t strictly true. Instead of a nose and eyes, slugs have four retractable tentacles on their head. The upper pair has a dual function, allowing the slug to see and smell. Meanwhile, the lower pair also has a dual function and is used for feeling and tasting. The slug’s mouth lies beneath the four tentacles.
Chimpanzees hunt monkeys

Chimpanzees are more like humans than many people are comfortable with. This similarity extends to their hunting abilities, and many family groups of chimpanzees are proficient hunters. Monkeys, such as red colobus, are frequently ambushed while even smaller prey, like lesser bush babies, are sometimes hunted using sticks that the chimpanzees have sharpened to a point with their teeth.
Otters hold hands when they sleep

Sea otters don’t hold hands when they sleep out of sentiment. Instead, scientists believe it’s to ensure that family members don’t drift away on ocean currents while sleeping. Another theory suggests that the hand-holding is an attempt to conserve body warmth as, although otters have thick fur, they have relatively little body fat to insulate them.
Polar bears have translucent fur

Polar bears often look yellow against the Arctic snows. However, this doesn’t mean that their fur is naturally yellow or, indeed, a dirty white. Instead, the hairs are actually translucent and the yellow tone is a result of reflected visible light. The translucency is an adaptation to help them blend in with their surroundings and so help them hunt. Moreover, translucent fur is better at retaining heat.
Bats have thumbs

Unlike birds, a bat’s wing is supported by its arm and four elongated fingers. However, it also has a thumb that provides no structural support to the wing. The thumb’s hook-like shape indicates its function: it’s used to allow the bat to cling to the surfaces of trees and rocks, and also for feeding.
You can tell a whale’s age from its ear wax

It might not be the most practical way of ageing a whale but, like trees, a whale’s earwax has rings that denote its age! Different species of whale excrete earwax at different rates, meaning that the age-assessment process is different for each species. With blue whales, for instance, each year of life is represented by two layers of wax: one light-colored and one dark.
Gorillas have unique nose prints

Forget fingerprinting! When it comes to gorillas, each individual is identifiable by its own unique nose print. Scientists studying wild gorillas use the distinctive features of this great ape’s nose to identify and keep track of individuals within a study group. Rather than the whorls of a human fingerprint, it’s the wrinkles above a gorilla’s nose that make up its unique “print”.
Tigers use infrasound

Tigers use sound in a variety of ways: to communicate with a potential mate, to warn off a rival, to call cubs, and even to disorientate prey. However, some of the most recent research suggests that it’s their use of infrasound that has the classically paralysing effect often observed in prey. It seems that what can’t be heard can still be felt – and is all the more terrifying for that.
Starfish use seawater instead of blood to pump nutrients around their body

Despite their name, starfish are not fish. They lack the defining features of a fish, which means they don’t have gills, scales, fins, a backbone or even blood. They’re invertebrates that belong to the same group of species as sea urchins and sponges – using seawater, not blood, to pump nutrients around their body.
The algae in a sloth’s fur depends on a moth

The algae growing in a sloth’s fur isn’t really a consequence of its famed slowness. Instead it’s a personal larder, containing unique microorganisms. Cultivating them depends on a small moth that also lives in the sloth’s fur. The moth lays its eggs in the dung, and the hatched adults will eventually fly into the canopy in search of their own sloth.
A grizzly’s bite can crush a bowling ball

The PSI rating of a grizzly bear bite is 975. This isn’t survivable for most animals that experience it – and, to give context, it’s sufficient force to crush a bowling ball. Avoiding an encounter with a grizzly is your best defence, and this doesn’t include running away as an adult grizzly can easily reach speeds of 35 mph.
Fleas can jump 200 times their body length

Perhaps you’ve heard people trying to compare how high a flea can jump to how high it could jump if it was human sized. However, let’s put that comparison to bed at once. Whilst it’s true that some species of flea can, indeed, jump around 200 times the length of their own body, a scaled up flea would suffocate immediately as its respiratory system only works on a flea-sized body…
The Pistol shrimp is louder than Concorde

Although it’s less than an inch long, the Pistol shrimp can emit a 218 decibel sound. This is louder than a gunshot and a Concorde. It makes the sound by snapping its claws together in a move that stuns its prey, allowing it to move in for the kill. Native to the warmer waters of the Mediterranean Sea, climate change has recently encouraged Pistol shrimps into cooler British waters.
Flamingos are naturally grey

When a flamingo chick hatches, it’s grey in color. What’s more, it will stay that color unless it receives the right nutrients. Wild flamingos achieve their famous pink coloration through eating food rich in beta-carotene. This includes certain species of algae, brine shrimp and brine fly larvae. In captivity, flamingos are fed supplements that ensure they, too, are as pink as we expect.
Dolphins enjoy getting high

We all know that as well as using it as a defensive maneuver to escape pursuing sharks or orca, dolphins seem to derive pleasure from leaping out of the water. Some, however, get their thrills elsewhere. Scientists have discovered that they enjoy snacking on toxic puffer fish. The tetrodotoxin they contain can kill a human in minutes but, in dolphins, it induces a trance-like narcotic state.
The horned lizard shoots blood from its eyes

In what has to be one of the most unlikely defence mechanisms anywhere in the natural world, a North American desert horned lizard protects itself by squirting blood out of its eyes. It’s the lizard’s last line of defence, employed when other strategies (run, fight, hide) have failed, but it’s frequently successful enough at frightening a predator to allow the lizard to escape.
Roosters have built-in ear plugs

If you’ve ever been disturbed by the morning cry of a cockerel, you might have wondered how the bird itself puts up with its own 100 decibel noise. It turns out that half of the bird’s eardrum is covered by tissue that dampens the sound. Furthermore, when it tilts its head back to crow, another piece covers the ear canal as a natural defence.
The giant squid is bigger than a bus

Giant squid are rarely sighted. We best gauge their size from tentacle marks left on sperm whales. The fact that it’s a battle for an animal the size of sperm whale to subdue the squid hints at its size: dead squid have been measured at lengths exceeding that of a school bus and some scientists think they could top 66 feet.
Pangolins can defend themselves from lions

A pride of lions can kill most things. Giraffe, elephant, hippo and buffalo all occasionally fall prey. However, the humble pangolin is a different matter. Though it weighs no more than seven pounds, this scaly mammal has a very effective defense: it rolls itself up into a scaly ball that’s great for football… but not so good for lunch.
A cockroach can survive without its head

If you’ve ever doubted the oft-repeated wisdom that a cockroach can survive a nuclear holocaust, perhaps this piece of information will help convince you: the insect is capable of surviving without its body. Not forever, of course – but for around a week, which is the period of time taken for it to dehydrate and starve to death.
Snails have thousands of teeth

It’s no wonder that snails wreak such havoc in vegetable gardens: each of the slimy creatures has thousands of teeth. Although these teeth perform a similar function to the teeth of other creatures, they’re not set in the snail’s “jaw”. Instead, they line the creature’s tongue – called a radula, and the snail uses its radula in a rasping motion to file off pieces of food.
The peregrine falcon is the fastest creature on earth

The fastest creature on land, sea or air is the relatively small peregrine falcon. Where a cheetah can reach a top speed of 75 mph and a Pacific sailfish around 68 mph, a stooping (which means “diving”) Peregrine regularly reaches 200 mph, with the highest measured speed reportedly being 242 mph.
Mexican walking fish can regenerate their brains

The Mexican walking fish, or axolotl, is a species of salamander. Salamanders are well-known for their regeneration abilities. However, the axolotl takes this to an extreme. As well as limbs, parts of eyes and spinal cord, it can even regenerate part of its brain if necessary – although research suggests that the new tissue does not have the same structure as the original.
Baby elephants suck their trunks for comfort

Like human babies, elephant babies sometimes feel in need of comfort. Instead of pacifiers, blankies, or thumbs, a baby elephant sucks its trunk. This is yet another use for an appendage that’s one of the most multi-functional in the animal kingdom. Breathing, feeding and smelling are just three of them – while the “fingers” at the trunk’s tip allow the animal to grasp things.
You won’t feel a vampire bat bite you

It’s a common fear: a bat that bites and sucks blood. In one way, the reality of the vampire bat is worse than any nightmare or horror story trope: its teeth are so fine and sharp that many people do not even feel the bite. In another, it’s not even worth thinking about, as the risk of being bitten is very low indeed as these bats prefer to feed from cattle.
Humans and chimpanzees share 98.8% of their DNA

If the idea of chimps that hunt makes you shudder, perhaps knowing that 98.6% of your DNA is the same as that of a chimp might give you pause for thought. However, our last common ancestor lived between six to eight million years ago. Not long in evolutionary terms, but still long enough for our species to have evolved to fill very different ecological niches.
A rhinoceros horn is not made from ivory

When people talk about ivory bans to protect elephants and rhinos, they’re not being entirely accurate. Though they appear similar, an elephant’s tusk is made from ivory (which is essentially dentine, the same material that teeth are made from), a rhino’s horn is made from keratin – or, compressed hair.
An elephant’s closest relative is a small rock-dwelling creature

The closest relative of the largest living land mammal is one of the smallest. The rock hyrax, also known as a dassie, coney, or rock rabbit, lives in sub-Saharan Africa and the Middle East. It shares a common ancestor with the elephant: the tethytheria, which became extinct around 50 million years ago.
A giant tortoise weighs as much as a brown bear

An obvious name, maybe, but the giant tortoise really isn’t playing around when it comes to size. At their biggest, these long-lived reptiles can grow to more than five feet in length and weigh over 500 llbs – which is more than a brown bear. The tortoises owe their long lives to a range of factors, including an average heart rate of just ten beats per minute.
Male pigeons produce milk

Both male and female pigeons share the responsibility for feeding their young. What’s more, they do this by producing “crop milk”. The crop is part of the bird’ lower esophagus – and it’s where undigested food is stored. Cells lining the crop produce this “milk”, which the adult bird regurgitates to feed its young. Nice.
Camels can drink 50 gallons in one minute

The “ship of the desert” owes much of its famed stamina to its ability to drink large amounts when it’s available – and quickly, too. 50 gallons in under a minute is not an uncommon rate. More importantly, the camel’s body stores the water effectively in its hump for future use and doesn’t excrete it unnecessarily in urine.
Woolly bats roost inside carnivorous plants

Hardwicke woolly bats of Borneo don’t bother with caves or trees. Instead, they roost inside a carnivorous plant that feeds off unwary bugs that get inside and then can’t get out again. Luckily the bat has no such problems – and that’s lucky for the plant too, as it relies on the bat’s droppings for around one-third of its nitrogen needs.
Oxpeckers live up to their name

It’s true that oxpeckers perform a useful service for large ungulates by removing ticks, flies and other pests from fur and skin. However, these sharp-beaked birds do a whole lot more than this. They have also been observed deliberately inflicting small wounds on their large hosts and in keeping existing wounds open – apparently so they can feed on the resulting blood.
Honeyguide birds talk to people

Recent research underlines the depth of the relationship between the African honeyguide bird and local tribespeople. Suggesting that both have evolved in symbiosis, birds and people “talk” to each other with a wide range of gestures and specific sounds that are used only during the search for a bees’ nest.
Male seahorses get pregnant

In an adaptation found nowhere else in the animal kingdom, male seahorses and their close relative, the pipefish, become pregnant and gestate the young. They even give birth, expelling the fry in a series of muscular contractions. At this point, though, their job is done and the babies are on their own.
Dementor wasps turn cockroaches into zombies

The dementor wasp turns zombie folklore into real-life horror. When it’s time to breed, the wasp finds a cockroach and stings it on the head. The injected toxin doesn’t kill the cockroach, but removes its ability to control its own movements. Instead, the roach will follow the wasp to its nest, where it becomes living food for wasp larvae.
The naked mole rat can survive without almost any oxygen

Oxygen is essential to life, but the almost-blind naked mole rat can survive in environments with levels of oxygen low enough to kill anything else. The adaptation is a result of the mole rat’s habitat: frequently crowded underground burrows with very low oxygen concentrations and correspondingly high carbon dioxide levels.