Hedgehog, common name for any of several spiny mammals that are similar in appearance to the porcupine, but more closely related to the mole and shrew (see Insectivore). The hedgehog, which is found in Europe, Asia, and Africa, has a coat of long, stiff, pointed spines on its back. The fur on its underside is soft. Hedgehogs average 25 cm (10 in) in length and range in color from light tan to black. They have pointed snouts, small eyes, short legs, and vestigial tails.

When threatened, the hedgehog rolls itself into a ball by the action of powerful muscles that arise from the head and neck on each side and loop around the rump. In this position its spines project in all directions. Hedgehogs conceal themselves in hedgerows during the daytime and emerge at night to hunt. They eat insects, worms, frogs, snakes, mice, and birds' eggs. European hedgehogs hibernate during the wintertime, but their torpor is not deep and they occasionally awaken and emerge from their nest of dry leaves to hunt food. In July or August the European hedgehog gives birth to four to eight young.

Related to the hedgehog are the furred hedgehogs, or gymnures. One species, commonly called the moon rat, inhabits lowland areas of Borneo, Sumatra, and the Malay Peninsula.

Scientific classification: Hedgehogs belong to the family Erinaceidae. Eurasian hedgehogs are classified in the genus Erinaceus, African hedgehogs in the genus Atelerix, long-eared desert hedgehogs in the genus Hemiechinus, and desert hedgehogs in the genus Paraechinus. Furred hedgehogs constitute the genera Podogymnura, Echinosorex, and Hylomys. The moon rat is classified as Echinosorex gymnurus.