Only a few mammals are known to produce venom and the slow loris is one of them. It mixes the secretion from a gland on the underside of its arm with its saliva to produce a toxin. It applies the toxin on its body when provoked, or to protect itself or its young from predators such as clouded leopards, binturongs and palm civets. A toothcomb on its lower jaw helps transfer the toxin. Toothcombs are comb-shaped incisors used to detangle fur and to get rid of debris trapped within. On its second toe is a toilet claw that provides additional help in grooming. Urine is used to scent mark territory and to communicate with other lorises.

Known for its slow and deliberate gait, the slow loris is surprisingly swift when striking at prey that is within reach. The grip of its hind feet is so strong and its backbone so flexible that it can twist around extensively, above and below branches, even hang upside down while using its hands to forage or to capture prey. A truly arboreal primate, it is almost never seen out of the treetops.

The dark patches around its eyes remind one of a clown, hence its name ‘loris’, which means clown in Dutch.