Olfaction is particularly important to lemurs, except for the indri, which lacks most common lemur scent glands and has a greatly reduced olfactory region in the brain. Olfaction can communicate information about age, sex, reproductive status, as well as demarcate the boundaries of a territory. It is most useful for communication between animals that rarely encounter each other. Small, nocturnal lemurs mark their territories with urine, while the larger, diurnal species use scent glands located on various parts of their anatomy. The ring-tailed lemur engages in "stink fights" by rubbing its tail across scent glands on its wrists, and then flicking its tail at other male opponents. Some lemurs defecate in specific areas, otherwise known as latrine behavior. Although many animals exhibit this behavior, it is a rare trait among primates. Latrine behavior can represent territorial marking and aid in interspecies signaling.
