A hedgehog is any of the small spiny mammals of the subfamily Erinaceinae and the order Insectivora. There are 15 species of hedgehog in four genera, found through parts of Europe, Asia, Africa, and New Zealand. more...
There are no hedgehogs native to the Americas or Australia.
Hedgehogs are easily distinguished by their spines, which are hollow hairs made stiff with keratin. Their spines are not poisonous or barbed and, unlike the quills of a porcupine, cannot easily be removed from the animal. However, spines normally come out when a hedgehog sheds baby spines and replaces them with adult spines around their first year. Under extreme stress or sickness (often both), a hedgehog will lose spines.
Hedgehogs are most closely related to gymnures and other insectivores, including moles, shrews, tenrecs and solenodons.
A defense that all species of hedgehogs possess is the ability to roll into a tight ball, causing all of the spines to point outwards. However, its effectiveness depends on the number of spines, and since some of the desert hedgehogs evolved to carry less weight, they are much more likely to try to run away and sometimes even attack the intruder, trying to ram into him with their needles, leaving rolling as a last resort. This results in a different amount of predators for different species: while forest hedgehogs have relatively few, primarily birds (especially owls) and ferrets, smaller species like long-eared hedgehogs are preyed on by foxes, wolves and mongooses.
All hedgehogs are primarily nocturnal, although different species can be more or less likely to come out in the daytime. The hedgehog sleeps for a large portion of the daytime either under cover of bush or grass or rock or in a hole in the ground. Again, different species can have slightly different habits, but in general hedgehogs dig out dens for shelter. All wild hedgehogs can hibernate, although not all do; hibernation depends on temperature, abundance of food and species. Hedgehogs are fairly vocal, and communicate not only in a series of grunts and snuffles, but sometimes in loud squeals (depending on species).
Hedgehogs occasionally perform a ritual called 'anointing'. When the animal comes across a new scent, it will lick and bite the source and then form a scented froth in its mouth and paste it on its spines with its tongue. This camouflages the hedgehog with the new scent of the area and provides a possible poison or source of infection to any predator that gets poked by their spines.
Although belonging to insectivore family, hedgehogs are almost omnivorous. Hedgehogs feed on insects, snails, frogs and toads, snakes, bird eggs, carrion, mushrooms, grass roots, berries, melons, and watermelons. In fact, berries constitute a major part of Afghan Hedgehog's diet in early spring after hibernation. The hedgehog is occasionally spotted after a rainstorm foraging for earthworms. Although forest hedgehogs, most well-known to Europeans, are indeed mainly insectivores, this is not necessarily true for other species.
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