A rainforest is rich in wildlife diversity and its dense canopy layer is teeming with more animals than any other part of the forest. The canopy trees and their branches -- just below the emergent layer of the tallest trees of the rainforest -- hold a bountiful supply of fruit, seeds, nuts and leaves to feed a broad range of animals.

Many species of monkeys scurry through the canopy. They grasp branches with long, prehensile tails and use their hands to forage. Species include howler monkeys, spider monkeys and sakis. According to the Smithsonian Tropical Research Institute, they often follow regular routes through the trees. Howler monkeys claim their territory with a call that can be heard more than a kilometer away.

Insects are the most abundant inhabitants of the rainforest. The Smithsonian Tropical Research Institute reports that scientists found more than 950 beetle species in a single tree in Panama. Many insects of the rainforest are tropical varieties commonly found in North America, such as bees, butterflies, ants and wasps.

Where there are insects, there are animals that thrive on them. The pygmy anteater—about the size of a squirrel—is equipped with a prehensile tail that makes it well suited to living in trees. Its long sticky tongue enables it to suck up a steady diet of ants and termites.

With its large, colorful bill, the toucan squashes fruit and berries and tears off pieces of larger fruit. Toucans play an important role in the rainforest, dispersing seeds from the fruit they eat. Forty different varieties of this bird live in the canopy layer of Central and South American rainforests.

The bright colors of poison-arrow frogs warn other animals that they are poisonous. Though these frogs are only about the size of a man’s thumbnail, their poison -- used by native hunters on the tips of arrows -- is lethal. Only a millionth of an ounce can kill a dog.

Macaws, the largest of all parrots, are on the endangered species list because of both rainforest destruction and their value to poachers for sale as pets. Their long, pointed wings give them swift flight and their sharp, strong, hooked beak helps them eat nuts, fruits and seeds.

Sloths rarely leave trees. They are nocturnal and can sleep upside-down for up to 18 hours, curled in a ball to blend in with the tree while holding tightly to the branches with their hooked claws. They have a slow metabolism, needing little food. Their diet consists of fruit, buds, leaves and young twigs.