Monkeys are highly intelligent, adaptable primates found across tropical forests, grasslands, and mountainous regions worldwide . They are divided into two major groups: New World monkeys , which live in the Americas and often possess prehensile tails used like an extra limb, and Old World monkeys , native to Africa and Asia, which lack these gripping tails but frequently feature specialized cheek pouches for storing food. As omnivores, their diets primarily consist of fruits, leaves, insects, and small animals. Known for their complex social structures, monkeys live in family groups called troops , where they communicate through a sophisticated mix of vocalizations, body language, and grooming rituals that reinforce social bonds.