Eight things the squirrel in the yard isn't telling you · Deep Cuts

A squirrel files its nuts like folders

A tree squirrel can bury several thousand nuts in a single autumn, and it doesn't scatter them at random. Tracking wild fox squirrels by satellite, researchers found the animals sort their hoard by kind, burying all the walnuts in one area and all the almonds in another. Grouping caches this way, the same trick people use to memorise a long number, eases the memory load and helps the squirrel recover more of its buried food months later.

A watched squirrel only pretends to bury

When a squirrel thinks it is being watched, it puts on a show. It digs a hole, makes the motions of dropping in a nut, then covers the empty spot and scurries off with the real prize still tucked in its cheek. The fakery ramps up sharply when rival squirrels or thieving jays are nearby, and switches off when no one is around, a flicker of tactical deception that hints the animal grasps what a rival can and cannot see.

A squirrel comes down a trunk head-first

Most climbing animals can scramble up a tree far more easily than down it. A squirrel solves the problem with its ankles: it can swivel its hind feet almost a full half-turn backward, so the claws point up the trunk even while the animal faces the ground. With its rear paws hooked into the bark like grappling hooks, it can plunge down a vertical trunk head-first at full speed.

This squirrel flashes a heat signal at snakes

A ground squirrel facing a rattlesnake does something invisible to our eyes: it pumps warm blood into its tail, raising its temperature. Rattlesnakes hunt partly by sensing heat through pits on their faces, so the glowing-hot, waving tail reads as a larger, bolder, wide-awake opponent, and the snake backs off, coiling defensively instead of striking. Against gopher snakes, which have no heat pits, the squirrel never bothers to warm its tail.

Squirrels wear eau de rattlesnake

Some ground squirrels chew on the skin a rattlesnake has shed, then lick the chewed-up scent across their own fur. Coated in the smell of their main predator, they become harder for a hunting snake to detect, useful especially while they sleep in their burrows. The pups and females, the squirrels most at risk of being eaten, do it far more often than the larger males.

The oak forest was planted by forgetful squirrels

A single squirrel may bury thousands of acorns in a year and never dig perhaps a quarter of them back up. Each forgotten nut is left exactly where a young oak needs to start: underground, spaced apart, away from the parent tree. Studies of mixed hardwood forests credit squirrels with the majority of new oak seedlings. The animal that looks like it's stealing the forest's seed is quietly sowing the next forest.

Flying squirrels can't fly — they hang-glide

A flying squirrel never flaps. Between its wrists and ankles stretches a furred flap of skin, held taut by a little spur of cartilage at the wrist, that turns the animal into a living kite. Launching from high in a tree, it glides on that membrane and steers with its flattened tail, crossing tens of metres between trunks, with the longest recorded glides reaching well over a hundred metres, before swooping up to land.

Flying squirrels secretly glow pink

By daylight a flying squirrel is plain brown. Shine ultraviolet light on one, though, and it blazes bubblegum pink. The discovery came by accident in 2019, when a researcher swept a UV torch across his garden and one at the bird feeder lit up. Checking museum skins, scientists found the glow only in the New World flying squirrels and not in their day-active cousins. Why these night-gliders fluoresce is still unknown.