According to the UC Davis California National Primate Research Center, a wild monkey's diet consists of fruits, seeds, roots and insects. Monkeys that live in zoos or wildlife preserves are fed fresh fruits and vegetables and Monkey Chow. Monkey Chow is a chicken-based kibble that is fortified with vitamins and nutrients.
Monkeys have extremely high metabolisms and typically eat several times a day. While the common belief is that all monkeys love bananas, the reality is that monkeys enjoy bananas as much as they enjoy other fruits. The types of fruit that monkeys eat also depends greatly on their habitat. In certain wildlife preserves, it is illegal for humans to feed the monkeys. While feeding monkeys seems relatively harmless, it can actually cause the monkeys to lose their fear of humans and become overly aggressive. Over-feeding monkeys can also contribute to over-population.
It is also common for wild chimpanzees to occasionally eat monkeys when food sources are scarce. The largest monkey species is the baboon. The smallest monkey species is the pygmy marmoset. The pygmy marmoset is approximately 6 inches long. Monkeys have existed for millions of years, and there are more than 260 known monkey species in the world.