According to How Stuff Works, monkeys are a large group of mammals that vary greatly in appearance and behavior. However, they share some common traits, such as intelligence, the tendency to live in social units and using their feet like hands.
Monkeys are very social animals that usually eat, sleep and travel in groups. Some monkeys, such as the South American howler, live in large clans made up of several families, while others live in smaller groups containing just a few adults – usually an alpha male, several females and their offspring. Most monkeys give birth to only one baby at a time. These family groups often hold and defend specific territories.
Almost all monkeys hunt and feed during the day, and many species are omnivorous. Insects, lizards, eggs, leaves, shoots, grain, fruit and birds are all common foods in a typical monkey diet, though some species are known to eat shellfish as well.
Monkey habitats are quite varied. They can be found throughout Asia, Africa and Central and South America, and they populate grasslands, jungles and rocky terrain. In some parts of the world, certain species, such as Hanuman langurs in India, have adapted happily to city life.
Many monkeys will act aggressively toward humans in the wild, but they are usually easily tamed if introduced to humans at a young age. Some monkeys, such as the capuchin, make intelligent and affectionate pets.