Hedgehogs | |
---|---|
European hedgehog | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Eulipotyphla |
Family: | Erinaceidae |
Subfamily: |
Erinaceinae G. Fischer, 1814 |
Genera | |
A hedgehog is any of the spiny mammals of the subfamily Erinaceinae, in the eulipotyphlan family Erinaceidae. There are seventeen species of hedgehog in five genera, found through parts of Europe, Asia, and Africa, and in New Zealand by introduction. There are no hedgehogs native to Australia, and no living species native to the Americas (the extinct genus Amphechinus was once present in North America). Hedgehogs share distant ancestry with shrews (family Soricidae), with gymnures possibly being the intermediate link, and have changed little over the last 15 million years. Like many of the first mammals, they have adapted to a nocturnal way of life. Hedgehogs' spiny protection resembles that of the unrelated porcupines, which are rodents, and echidnas, a type of monotreme.
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. Other names include urchin, hedgepig and furze-pig. The collective noun for a group of hedgehogs is array.
Hedgehogs are easily recognized by their spines, which are hollow hairs made stiff with keratin. Their spines are not poisonous or and unlike the quills of a porcupine, do not easily detach from their bodies. However, the immature animal's spines normally fall out as they are replaced with adult spines. This is called "quilling". Spines can also shed when the animal is diseased or under extreme stress.