Ants are the singlemost most numerous animals in the Amazon. Collectively, they exert a powerful ecological influence on the ecosystem, serving as herbivores, scavengers, soil conditioners and predators. Some species, such as the pomerine ants, are quite large, reaching up to one inch in length, with a painful sting. The most notorious of these is the so-called bullet ant or "conga" (Paraponera spp.). A number of other animals depend on ants, notably the anteater and antbirds. In terms of ecology, the leafcutter ant is among the most important. It serves as a major herbivore, consuming huge amounts of green vegetation, and thereby assisting in the turnover of nutrients in the rainforest.
The volcano-like turrets of red earth represent the above-ground portion of the nest of leaf-cutter ants (Atta sp.), but most of the nest is below ground. This species is a significant herbivore, responsible for consuming a large proportion of vegetation. However, they are fussy and only select certain plant species, which are then fed to a mutualist species of fungus.
When leafcutter ants are foraging, each worker ant cuts a neat section from a leaf, and then carries it like a trophy back to the nest. Here the leaf portions is composted with countless others. A fungus grows upon the leaf pile and breaks down the leaves. The ants then consume the fungal fruiting bodies for food.