Primates nurse their young with milk. The primate family, namely monkeys and apes, is one of the major groups of mammals. The word "Primate" comes from the Latin word "primus", which means "first". Most primates live in tropical places; however, men, classified by Scientists as primates, live in almost all regions and climates of the world.
A few primates live on the ground, but most primates spend their time in trees because they have good eyes, grasping hands and feet, and their bodies are well suited to life in the trees. First, primates have large eyes to look straight forward; in addition, higher primates can focus both eyes on the same object and some primates also see colors. Second, besides many other mammals have claws, primates have flat nails on the end of their fingers and toes to help support enlarged pads, which is sensitive to touch and have nonskid ridges. Last, according to Gordon M. Shepherd (2004), “Comparisons of the decreasing size of the olfactory system relative to expansion of the visual, auditory, and somatosensory systems usually focus on the olfactory bulb and lateral olfactory tract, which are relatively small. “ That is to say, although primates among the most intelligent of mammals for most of them have large brains, but the part related to the sense of smell of their brain is relatively small, because they do not depend much on their smell(Humans Smell with Bigger and Better Brains) .
Primates have fewer young than most mammals because a mother bears only one or two young at a time, but the young primates stay with their mothers for a longer time, which allows them to learn more from their mothers and the group they live in.
Shepherd, G. M. (May 2004). The Human Sense of Smell: Are We Better Than We Think? PLoS Biology <http://www.plosbiology.org/plosonline/?request=get-document&doi=10.1371%2Fjournal.pbio.0020146 >(2005, Feb 28).