The smallest of the hoofed mammals, they stand 8 to 14 in. (20-66 cm) high at the shoulder, depending on the species. The body is rabbitlike, with an arched back; the legs are very slender and end in small feet; the snout is tapered and somewhat piglike. Their small size makes them easy and important prey for snakes, crocodiles, eagles, and forest-dwelling cats. The reddish-brown coat is spotted with white in most species. Chevrotains lack antlers but have tusklike upper canine teeth, used by the males for fighting. The upper incisors are lacking.
Solitary, nocturnal animals of thick forests, chevrotains browse on leaves, twigs, and fruit. They sometimes rest in the branches of low trees. The water chevrotain (Hyemoschus aquaticus) of Africa is always found near water and takes to the water when pursued. The other chevrotains (Moschiola and Tragulus species) are found from India to Indonesia and the Philippines, and some also can swim underwater. Chevrotains are classified in the phylum Chordata, subphylum Vertebrata, class Mammalia, order Artiodactyla, family Tragulidae.
In Malay folklore, the mouse deer plays the same role as the wily fox of European fables. The Malaysian-made Perodua Kancil car is named after the chevrotain, as it is a very small vehicle. The Telugu name for the animal is "Jarini Pandi", which literally means "a deer and a mouse". The word 'chevrotain' itself is French, and can be translated as 'little goat'.
In other respects, however, the chevrotains have primitive features, closer to non-ruminants such as pigs. They do not have horns or antlers, but both sexes possess enlarged upper canines The male's are prominent and sharp, projecting either side of the lower jaw. Chevrotains have short, thin legs which leave them lacking in agility but also helps to maintain a smaller profile which aids in running through the dense foliage of their environment. Other pig-like features include the presence of four toes on each foot, the absence of facial scent glands, premolars with sharp crowns, and the form of their sexual behaviour and copulation.
The largest member of the family is the Water Chevrotain of Africa, at about 80 cm in length and roughly 10 kilograms. It is regarded as the most pig-like and primitive of the four. The remaining three all prefer rocky forest habitats. The Lesser Mouse Deer of South-east Asia is the smallest of all ungulates, at a mature size as little as around 45 cm (18 inches) and 2 kg (4.4 lb).
Chevrotains are solitary animals, and usually interact only to mate. The young are weaned at three months of age, and reach sexual maturity at between five and ten months, depending on species. Parental care is relatively limited. Although they lack the types of scent glands found in most other ruminants, they do possess a chin gland for marking each other as mates or antagonists, and, in the case of the water chevrotain, anal and preputial glands for marking territory. Their territories are relatively small, on the order of 13-24 hectares, but neighbors generally ignore each other, rather than competing aggressively.
All four species depend for their survival on the retention of their fast-dwindling forest habitat and restriction of the bush meat trade.
The Hypertragulidae were closely related to the Tragulidae: