About the size of a rabbit, these ungulates have very long and thin legs; a rounded body; and a small, triangular head with a small pointed black nose and large eyes. They are an orange-brown color with a white belly, chest and neck.
Unlike many of their relatives, they do not have horns or antlers, but males do have small tusks (elongated canines) in their upper jaw which they use in fighting. When standing on all fours, their hindquarters are taller than their front end.
Larger Malay mouse-deer bodies measure about 29 inches (75 centimeter) long, with their tail adding another 3.5 inches (9 centimeter). Their shoulder height is about 13 inches (34 centimeter).
Larger Malay mouse-deer live in Thailand, Indochina, Sri Lanka, and the Malayan Peninsula, as well as in Sumatra and Borneo. They always live close to water and prefer to be in the undergrowth of dense forests. They create small trails through the thick brush of the forest as they travel.
In the wild, larger Malay mouse-deer eat a diet of fallen fruit and berries, aquatic plants, leaves, buds, shrubs and grasses. At the Smithsonian's National Zoo, larger Malay mouse-deer eat browse, alfalfa, kale, sweet potatoes, carrots, sweet potatoes and banana peels.
Male mouse-deer of this species have a large gland on their lower jaw that they rub against females in anticipation of mating. These animals breed year-round with a gestation period of about five months and will breed again within a couple of hours after birth. Because of this, females spend most of their adult life pregnant.
They usually have only one offspring at a time, though twin births occur rarely. The calves are well developed when born and are able to stand and be fully active 30 minutes after birth. They are weaned when they are two to three months old, and are sexually mature at 4.5 months.
Larger Malay mouse-deer can live up to 16 years in human care.
Habitat loss, forest degradation, hunting and the pet trade remain looming threats for the larger Malay mouse-deer. Many species are considered a food source for people in their native range as well. Their diminutive size has also created a demand for these animals in the pet trade.