Monkeys are intelligent, day-active animals that can learn to use tools and communicate with other monkeys. They are excellent climbers and are primarily arboreal, living in tropical or subtropical climates. They are also good swimmers. Unlike the great apes and humans, most monkeys are not bipedal; they walk on all fours and swing their arms from branch to branch.
Like most primates, monkeys have a wide range of emotions. They are able to express fear, anger and sadness, as well as happiness, contentment and affection. They can also become jealous, especially of things they consider to be their own. They also have a tendency to bite and scratch. Often this behaviour results in serious injuries to people. Some species of monkeys, such as squirrel monkeys, can even transmit bacterial diseases to people, including tuberculosis and hepatitis.
The term monkey applies to any of the world’s more than 300 species of nonhuman primates that are not considered apes or humans. Monkeys are generally small, hairy, and highly intelligent. They usually live in groups and are omnivorous, eating seeds, nuts, fruits, leaves, flowers, bark, roots, rodents, birds, insects, and even human food such as bananas.
In the wild, monkeys have a complex system of communication to warn other monkeys about predators. They will bang stones together to make loud noises and even send out signals using their facial expressions and body movements. For example, grinning (and exposing the teeth) may look like a smile to us but is actually a sign of aggression in monkeys. They can also communicate with each other by yawning, head bobbing and jerking their heads and shoulders forward. They can even spell words out with their fingers, but they don’t use the open-ended language that we do, where we can string letters and sounds together to create sentences.