Monkeys are masters of the treetops, with long tails that allow them to reach for plump fruits, juicy leaves, and even crawly critters. They’re omnivores, and their varied diets keep them energy-packed for their incredible swinging adventures.
Monkeys typically live in groups, called troops. The structure of the troop depends on the species: some are solitary, while others are highly social. A male monkey typically leads a group of females and other males, and he competes with other males to control the territory and mating rights of his troop.
Most monkeys are curious creatures. Their large brains and well-developed hands give them the flexibility to learn a wide range of skills. Some, like the Japanese macaque, spontaneously use objects as tools—for example, rocks to crack nuts. But they don’t quite achieve the cognitive level of great apes, such as chimpanzees and gorillas.
Monkeys communicate a lot, using their voices and bodies to warn each other of danger, mark their territories, call for a mate, and express emotions. They use a variety of vocalizations, including barks, grunts, squeaks, hoots, and wails, to get their points across. They can also read each other’s body language and facial expressions, and they use grooming to make up after a fight or show affection.
Some humans have close relationships with monkeys, keeping them as pets or using them for research in laboratories. But a few types of monkeys can carry viruses that can make humans very sick, or even kill them. Creutzfeldt-Jakob Disease (sometimes called “mad cow disease”), herpes B virus encephalitis, and rabies are some of the diseases that can be transmitted from monkeys to people.