Borneo alone has over 30 species of mammals, reptiles, and amphibians that can glide from one tree to another, which is a very efficient way of getting around in a rain forest. Mutual interactions between plants and animals are characteristic of rain forests. Many animal groups, but especially insects and birds, pollinate rain forest trees, as wind is not an effective pollinator for most plant species in this relatively closed environment. The insects receive food from nectar and other substances, and in return pollinate the next flowers they visit. After fruit is formed, rain forest plants more often than not use animals to disperse their seeds.
Some animal groups provide protection to a plant species and receive living quarters in return.
Ants are the most common and abundant animals found in rain forests, and they have evolved to occupy all strata, from the understorey to the emergents. Many tropical plants have hollow structures in their stems or twigs that stinging or biting ants use as homes. Ants supply nutrients to the trees and also in many cases protect them from leaf and seed predators. It is now generally accepted by scientists, though unfortunately not by many developers, that rain forests are of more potential value as a long-term sustainable resource when left more or less intact than when converted to pastures or other simplified habitats. Rain forests have built up the largest standing biomass of any plant community on earth, and they have done this almost independently of soil conditions by evolving nutrient recycling.