Epiphytes are plants that grow on other plants, and tank bromeliads hold water that a wide range of animals use. A strangler fig seed often starts growing in the branches of another tree, and the fig sends roots down its host tree to the ground and slowly strangles the host. Many rainforest trees have buttresses, large aerial extensions of their surface roots, and a single hectare (2.5 acres) of tropical rainforest can hold hundreds of species of trees. Tropical wet forests have more species of trees than any other biome, and many rainforest leaves have pointed tips that help water run off, and canopy leaves, which are leathery and drought-resistant, act as trillions of tiny solar panels, turning strong sunlight into energy. A scientist compares every giant tree in the Amazon canopy to an island in an ocean of trees.

Sloths live high in the trees of tropical rainforests, and algae grow on the fur of sloths, which move very slowly. You may have heard that sloths come down from the trees often, but a sloth's digestive system is so slow that it comes down from the trees only about once a week. Harpy eagles use their great talons to snatch up monkeys and sloths, and orangutans build nests to sleep in, and an orangutan's arms stretch out longer than its body, over 7 feet (2 meters) from fingertip to fingertip. Orangutan infants stay with their mothers for some six or seven years, until they can survive on their own. Gorillas live in groups called troops, and gorillas eat mostly plants and make nests to rest and sleep in. As of November 2026, most of the life in a rainforest lives up in the trees.

Lizards, snakes and frogs have their greatest diversity in the rain forest, including many groups found only there, and bats are the most diverse mammals in most tropical rainforests. As of November 2026, the Amazon is home to about 10 percent of the world's known species, and the Amazon rainforest is home to around 40,000 plant species, nearly 1,300 bird species and 3,000 types of fish. As of November 2026, the Amazon rainforest has more than 430 species of mammals and 2.5 million different insects. Scientists are still finding new species in tropical rainforests as of November 2026, and scientists did not know of okapis until 1901. The okapi, a rainforest animal of the Congo, is the only close living relative of the giraffe. Tropical rainforests are found in Central and South America and in Africa, and more animals live in the canopy than in any other layer of the rainforest.

Food can come in surprising ways. Poison dart frogs live in the wet tropical forests of Central and South America, and they are small, brightly colored frogs, most of them only about 2 inches (5 centimeters) long or less. You may have heard that poison dart frogs make all of their poison themselves. In fact, poison frogs raised on a diet of crickets and other non-poisonous insects in human care are not poisonous themselves. Ants learned to farm 50 million years ago, way before humans did, and the fungus the ants grow is the only food source for the leaf-cutter ant. In a leaf-cutter ant colony, smaller workers care for the young and farm the gardens, while larger workers collect leaves and maintain the nest. Leaf-cutter worker ants carry bacteria, called Actinobacteria, that produce antibiotics. In some ways, the fungus gardens of leaf-cutter ants act as an edible external digestive system.

Words to know

• epiphytes: plants on plants
• buttresses: big root supports
• algae: simple green growth
• fungus: mushroom-like organism
• colony: ant community