Offer a cat a spoonful of ice cream and it may well lick it. But not for the sweetness. It's tasting the fat.
Cats are missing a working copy of one of the two genes needed to build the sweet taste receptor. In most mammals that pair is intact. In cats, one half is a broken remn…
If you've ever caught your rabbit tucked into a ball, nose to bottom, quietly eating something, you didn't see a bad habit. You saw digestion finishing its job.
Rabbits produce two kinds of droppings. The dry round pellets you sweep up are waste. The other kind, caecotrophs, com…
Most amphibians climb out of the water. The axolotl simply refuses.
Frogs and newts hatch as aquatic larvae with feathery external gills, then metamorphose: gills shrink, lungs take over, and they head for land. The axolotl keeps the baby kit for life. Adults stay in the water,…
A galloping horse is running flat out, lungs heaving — and its mouth has nothing to do with it.
Horses are obligate nasal breathers. The soft palate sits in a long seal below the epiglottis, effectively shutting the mouth off from the airway. Every breath, resting or racing, goe…
Look a goat in the face and something feels slightly off. The pupil isn't round — it's a wide black letterbox, lying flat across the eye.
That shape is prey animal engineering. The horizontal slit works like a panoramic window, giving goats, sheep and other grazers a hugely wide…
A gecko can hang from a pane of glass by one toe — and there isn't a drop of glue involved.
Look closely at the underside of those feet and you'll see ridges, like fingerprints. Each ridge is covered in millions of microscopic hairs called setae, and each seta splits again into…
Hold a budgie under a UV lamp and parts of its face light up like a highlighter. The yellow feathers on the crown and cheeks fluoresce — they absorb ultraviolet light and throw it back as a glow.
To us, that's a party trick. To another budgie, it's part of the picture. Birds hav…
A tortoise doesn't live in its shell the way a hermit crab lives in a borrowed one. It can't climb out. The shell is part of its skeleton.
Over evolutionary time, the ribs and vertebrae of early turtles flattened and fused into a bony dome, with the shoulder blades ending up ins…
Scientists handed a pig a joystick, and the pig played.
The work began decades ago at an American agricultural university, where researchers wanted to know how much a pig could really understand. They modified an arcade-style setup: snout on the joystick, cursor on the screen, h…
A neuroscientist spent years tickling rats in a lab, and the rats kept coming back for more.
In the 1990s, Jaak Panksepp noticed that young rats at play made a particular chirp at around 50 kilohertz — far above human hearing. When he tickled them, especially on the nape and bel…
Hold a piece of parsley right in front of your rabbit's face and watch it fumble. Not because it's clumsy — because that exact spot is invisible.
Rabbit eyes sit high on the sides of the skull, giving a field of view close to all the way around. Brilliant for spotting a buzzard.…
Look closely at the top of a bearded dragon's head, between the eyes and slightly back. There's a small pale scale, a little like a freckle. That's a parietal eye — a genuine third eye, wired to the brain.
It doesn't form pictures. No lens worth speaking of, no colour, no detail…
A grey parrot once looked in a mirror and asked a question nobody had taught him: what colour am I?
His name was Alex, bought from a pet shop in the late 1970s by the scientist Irene Pepperberg. At the time, most researchers assumed birds could only mimic. Pepperberg spent three…
A horse can doze on its feet without falling over. Tendons and ligaments in the legs lock the joints into place — the stay apparatus — so the body rests while the frame holds itself up. It costs almost no effort.
It's a prey animal's bargain: stay upright, stay ready to run.
Bu…
The goldfish in the corner of your living room is listening. Not metaphorically. It has a better sense of hearing than most fish in the sea.
Goldfish, carp, tetras, catfish and their relatives share an unusual piece of anatomy: a chain of tiny bones linking the swim bladder to t…
Your rabbit will never throw up. Not from a bad meal, not from a swallowed clump of fur, not ever.
The anatomy is simply built the other way. A rabbit's stomach sits behind a powerful one-way valve, and the muscular reflex that lets dogs, cats and people vomit just isn't there.…
A female ferret can, quite literally, die of waiting.
Ferrets are induced ovulators. A jill releases eggs only in response to mating. Come into season in spring, with no male and no veterinary intervention, and she simply stays in season — sometimes for months, oestrogen high th…
For most of the 20th century, scientists were sure of one thing: the adult brain does not make new neurons. You get what you're born with, and after that it's downhill.
Then researchers started looking closely at canaries.
Male canaries learn and revise their songs, and the bra…
Offer a cat a spoonful of ice cream and it may well lick it. But not for the sugar. Cats are the one group of mammals known to be effectively blind to sweet taste.
The reason sits in their DNA. Sweet taste in mammals depends on a receptor built from two proteins. In cats, the ge…
Somewhere around dawn, while you were asleep, your rabbit ate a meal you have never served.
Rabbits are hindgut fermenters. Grass and hay are tough stuff, so the fibre is sorted in the gut: the indigestible bits become the round, dry pellets you sweep up, while finer material is…
Hold a budgie under a UV lamp and parts of it glow. The yellow feathers on the crown and cheeks fluoresce — a soft, lantern-like shine that is completely invisible to us.
Budgies, like many birds, have four types of colour-sensing cone in the eye instead of our three. The extra…
Look a goat in the eye and something odd looks back: the pupil isn't round, it's a horizontal slot, like a letterbox.
Sheep have them too. So do horses, cattle and deer. It isn't decoration. That wide slit lets in light from a very broad strip of the world, giving grazing animal…