The luxuriant growth in jungles does not allow much light to reach the forest floor. Ferns and mosses manage to survive, but grasses and small herbs do not fare well in this relatively dark environment. The forest floor serves as a depository for the leaves and twigs that fall from jungle trees. This vegetable litter provides sustenance for fungi and bacteria. It also furnishes nourishment or shelter for such small animals as ants, termites, scorpions, millipedes and cockroaches. The type of larger animals that roam about on the forest floor differs from jungle to jungle. Tigers prowl about in India, while leopards walk the forest floor in Africa when they are not climbing in the trees. Other jungle denizens are gorillas, tapirs, lizards and the giant anteater.
The understory consists of trees and shrubs that do not grow high enough to reach the canopy. Epiphytes, such as the bird's nest fern, staghorn fern, lichens and mosses, grow on the trunks and branches of trees in the understory. Lianas traverse the understory, climbing up tree trunks in an effort to reach the sunny canopy. Insects, such as butterflies and ants, thrive in the understory, as do tree frogs, monkeys and bats. Some of these animals do not always stay in the understory. In particular, monkeys are agile climbers and move from level to level. Birds such as the owl fly about in the understory, and snakes are also present.
Canopy trees grow considerably higher than understory trees and form a sort of leafy roof over the jungle. The shade cast by canopy trees is enhanced by the vegetation of vines that have climbed from the forest floor. The canopy itself is sunny, and a host of plants, such as orchids and bromeliads, thrive in the life-giving sunshine. The luxuriant canopy growth provides ample food for animals. Parrots, toucans and monkeys partake of the bounty, and fruit bats sojourn in the canopy. The sloth makes its home there, and even jaguars occasionally make an appearance. Insects are also present, especially pollinators, but a greater number of insects live in the understory.
The emergent layer consists of a few extra tall trees that tower above the canopy. They are typically evergreen hardwoods. Their elevated position exposes them to the unabated force of the wind, the rain and the heat of the sun. As a result, these lofty trees need leaves that resist desiccation and well-buttressed roots to keep them from toppling over. However, exposure to the wind helps them by dispersing their seeds. Eagles prefer the emergent layer. For example, in the forests of the Amazon River basin, harpy eagles use these towering trees as nesting sites. Other animals, such as monkeys, venture into these lofty heights.