Monkeys seem to be a lot like us. They are curious. They show their feelings on their faces. And they have two arms and two legs, ten fingers and ten toes, and human-looking eyes and ears. This is not too surprising, because people and monkeys are both primates. Scientists divide monkeys into two groups: Old World and New World monkeys. New World monkeys live in Central and South America. They are known for having prehensile tails, which can grasp branches like a third hand. Old World monkeys in Africa and Asia do not have prehensile tails; instead, they are recognized by their smaller, more closely placed nostrils, and some of them have callouses on their back ends like built-in seat cushions.