The Java mouse deer is the smallest living ungulate! On average, they reach 18 inches long, 12 inches tall, and weigh up to 4 pounds.

Their thin, small legs have the diameter of a pencil. Unlike regular deer, Java mouse deer do not have horns or antlers. Instead, male Java mouse deer will grow small tusk-like teeth from their canines that protrude downward from their upper jaw.

Females are easily distinguished as they are the smaller of the sexes and don’t have long canines.

The only proven territory that the Java mouse deer is found is in Java, Indonesia. Java mouse deer prefer high elevation tropical forests but can also be found at lower elevations. They will spend the day roaming through thick vegetation and tunnels, and their night in the higher and drier areas.

Java mouse deer can be classified as folivores meaning they eat primarily shrubs, leaves, shoots, fungi, and other vegetation. They aren’t the picky eaters and will usually eat anything they can find while foraging.

Java mouse deer will live in a small monogamous family group. Once pregnant, the female mouse deer will carry her fawn for around five months. A single fawn is born weighing only about 13 ounces and will be able to stand on its own as quickly as 30 minutes after birth! The fawn looks like a miniature adult Java mouse deer and will be fully weaned after 12 weeks.

Java mouse deer will use their small tusks to defend themselves and their mate against danger.

When frightened, Java mouse deer will let out a shrill cry or quickly tap their hooves on the ground to confuse their predator. These quick hoof beats have been known to reach up to seven beats per second!