The European common rabbit, Oryctolagus cuniculus, is native to S Europe and Africa, but is now found, in its domestic varieties, throughout the world; wild varieties have also been introduced in some places, such as England. All domestic rabbits, including the so-called Belgian hare, belong to this species. Wild common rabbits are up to 16 in. (41 cm) long and usually weigh 2 to 3 lb (0.9–1.4 kg). They have soft, thick fur, usually grayish brown above and white below. The tail is usually carried upright when the animal runs, exposing the white undersurface. Common rabbits live in elaborate systems of adjoining burrows called warrens. The young are suckled in a special burrow, dug by the mother at a distance from the warren and lined with a nest of her own fur. The entrance to this burrow is plugged with earth when she is away. Domestic rabbits, which may be various colors but are commonly white, are bred for food and for their fur, which is much used in making fur trim and felt. They are also frequently used as laboratory animals and are kept as pets.