Primates have the following characteristics: 1) Eyes located in the front part of the face allowing them to see things sterically; 2) Big toe on front legs can face the other enabling smooth grasping ability; and, 3) Brains have considerably developed compared with other animals. Characteristics 1 and 2 are very useful for arboreal life. Tree shrews and Insectivore such as moles have similar characteristics in their length of muzzle, eye location, brain and neuron development to that of primates. Their ancestors are considered to be the direct ancestors of primates.