Sun Bears get their name from the yellow-ish mark on their chests which is said to resemble the rising sun. However, these marks can vary and may be completely lacking. They are the smallest of the eight species of bear.

Little is known about the social habits of Sun Bears. They are primarily nocturnal, and spend much of the day sunbathing or resting. They are tree climbers and spend most of their time amongst the branches, often on makeshift nests they have built out of branches, these can be as high as seven metres off the ground.

Sun Bears will mate at any time of year, as they do not hibernate in winter like other bear species. Gestation lasts 90-110 days and either one or two tiny babies will be born. The babies remain with their mother for quite some time, learning how to find food and fend for themselves. They reach sexual maturity at between three and four years of age.

 Sun Bears have been known to live up to 25 years in captivity, but it is not known how long they live in the wild.