Deer are the ruminant mammals forming the family Cervidae. They include for example Moose, Red Deer, Reindeer, Roe and Chital. Animals from related families within the order Artiodactyla (even-toed ungulates) are often also considered to be deer these include muntjac and water deer. Male (and a few female) deer of all species (except the Chinese Water deer who only have short tusks instead) grow and shed new antlers each year in this they differ from permanently horned animals such as antelope these are in the same order as deer and may bear a superficial resemblance. The musk deer of Asia and Water Chevrotain (or Mouse Deer) of tropical African and Asian forests are not usually regarded as true deer and form their own families, Moschidae and Tragulidae, respectively.