Their favorite position to sleep is upright against a tree trunk or branch, using their tails for support. Tarsiers sleep in different places in their territory daily, and arise from slumber at sundown or during early evening, when insects are most active. Their offspring, which they sometimes carry in their mouths, are usually left in deep vegetation while the mother hunts. Tarsiers keep in constant contact with their offspring through high-pitched calls, yells and noises. Tarsiers' eyes, which can weigh more than their brains, are essential in their capture of their prey.
Tarsiers have excellent night vision.
Also, their ears are very sensitive, and they can hear long distances. Upon detecting predators, the tarsier closes its eyes the predator is almost directly on top of it. At this point, it opens its huge eyes and bares its sharp teeth in an effort to scare off the predator. Tarsiers are known for their extraordinary leaping abilities. On average they can leap 2m in distance and up to 1.5m in height.