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.
[3] Hedgehogs' spiny protection resembles that of the unrelated
porcupines, which are
rodents, and
echidnas, a type of
monotreme.