A hedgehog is any of the spiny mammals of the subfamily Erinaceinae, which is in order Erinaceomorpha. There are found in Europe, Asia, Africa and New Zealand (by introduction). There are no hedgehogs native to Australia, nor the Americas. Hedgehogs share distant ancestry with shrews, 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, insectivorous way of life.