The scientific name for the genus that includes the three species of Eurasian hedgehogs is Erinaceus. The hedgehog family’s scientific name is Erinaceidae, and it includes hedgehogs and gymnures.
The normal heartbeat for one species of hedgehog is about 190 beats every minute. That rate drops to about 20 beats a minute while it hibernates in winter.
The normal lifespan of a hedgehog is about seven years.
The name ‘hedgehog’ came into use around the year 1450, derived from the Middle English ‘heyghoge’, from ‘heyg’, ‘hegge’ = hedge, because it frequents hedgerows, and ‘hoge’, ‘hogge’ = hog, from its piglike snout.
Hedgehogs have many alternate defense mechanisms. In most situations a hedgehog will flee rather than confront a threat, rolled up in a ball or not. All hedgehogs possess the stamina to run, many can make 4.5 miles per hour or better, and are particularly adept at climbing steep walls, trees, and fences and even swimming.
When you curl up to go to sleep, you’re just getting comfy. When a hedgehog curls up to go to sleep, it’s for protection. Hedgehogs have prickly spines everywhere except on their face, legs, and bellies. By curling into a tight ball and tucking in their heads, tail, and legs, they protect the parts of their bodies that do not have stiff, sharp spines. Often compared to pincushions, hedgehogs depend on their spines for defense—both while they sleep and when they face enemies.
When hedgehogs are born—up to seven in a litter—their spines are soft and short. Soon after birth, their spines harden, becoming stiffer, sharper, and longer. Babies stay in the nest until they’re about three weeks old. By that time, their eyes are open, their spines are effective, and they can safely follow their mother outside the nest as she looks for food
Tops on the hedgehog’s menu are insects, followed by small mice, snails, lizards, frogs, eggs, and even snakes. When a hedgehog goes after a snake to eat, its spines act as a shield against the reptile’s bites.
Hedgehogs sometimes add extra protection to their spines by “self-anointing.” Immune to poisons in some plants, hedgehogs sometimes eat those plants and then make a frothy saliva in their mouths. The hedgehogs then lick their spines, spreading the saliva with the plant’s poison all over the spikes. Some scientists think this is the hedgehog’s way to make itself even more irritating to prowling predators.
Though hedgehogs mainly stay on the ground, they swim quite well and even climb trees. If one is up in a tree and wants to get down quickly—or falls—its spines come in handy once again. When the hedgehog hits the ground, it bounces, unhurt, because of the spines.