Abstract: Most primates limit their activities to one particular segment of each 24-hour day. Rather than being strictly diurnal and nocturnal, they seem to be active at intervals throughout a 24-hour day, an activity pattern that is called cathemeral. Each of these ways of life has its advantages and disadvantages. For most primates, the day is generally divided among three main activities: feeding, moving, and resting. The distribution of activities throughout the day is usually not random. Primate diets have generally been divided into three main food categories: fruit, leaves and fauna. In addition to particular nutritional and mechanical features, primate foods may vary considerably in their distribution and availability in both space and time. No other order of mammals displays the diversity of locomotors habits seen among primates. Primate locomotors habits can be divided into several major categories: leaping,arboreal and terrestrial guadrupedalism, suspensory behavior and bipedalism. In addition to locomotion, primatologist also pay careful attention to differences in primate postures—the way primates sit, hang, cling, or stand. In many instances, feeding postures may be as important as locomotion in the evolution of the species.