The sloth bear (Melursus ursinus) is something of an anomaly. In terms of diet, this medium-sized bear has more in common with anteaters than other bears. It was named for its ungainly appearance and long, curved claws, but in fact can run faster than a human and is very active and noisy at night. Its preferred food is termites, and to this end it has developed a gap in the front teeth through which it sucks up the insects. It can open and close its nostrils at will, and a hairless patch on the front of the snout protects it against the termites' defensive secretions.
A sloth bear at work on a termite nest can be heard a long distance away through the forest. The bear usually lies alone at night. If surprised by humans in the undergrowth, it rears up on its hind legs and brandishes its heavy claws. Sloth bears have been known to injure humans, but they usually run away when disturbed.