旧世界猴, or "Old World monkeys," are a group of primates that primarily inhabit Africa and Asia. They belong to the family Cercopithecidae and are characterized by their downward-facing nostrils, non-prehensile tails, and a more robust body structure compared to New World monkeys. These monkeys are known for their diverse diets, which can include fruits, leaves, and insects. Some well-known species include the baboons, macaques, and mandrills. Old World monkeys are social animals, often living in troops that exhibit complex social structures and behaviors.