There are over 250 different types of monkeys that can be divided into two main groups: New World monkeys and Old World monkeys. Monkeys vary significantly in size, from around 1 meter tall up to 35 kg in weight. They eat a variety of foods including fruits, leaves, seeds, nuts, flowers, insects, spiders, eggs and small animals. Some notable types of monkeys discussed include howler monkeys, known for their loud howls, baboons which live in groups of around 100 and communicate using vocalizations and tail positioning, chimpanzees which are closely related to humans, and spider monkeys which use their long tails to swing through trees.