A wombat is an Australian animal, roughly the size of a small, very solid dog, with short legs, thick grey-brown fur, a broad flat head and almost no tail. Like the kangaroo and the koala it is a marsupial — the mother carries her tiny baby in a pouch, a pocket of skin on her body — and unusually, a wombat's pouch opens backwards, so that soil does not fill it while she digs. Wombats dig a great deal: they live underground in long burrows, come out at night to eat grass and roots, and are famous among Australians for two things. They are surprisingly fast for such a heavy animal, and their droppings are cube-shaped, which stops them rolling off the rocks the wombat uses to mark its territory. The word is used in ordinary English only for the animal; unlike some animal words it has no common insulting or figurative use.