The fungus growing ants are found throughout Central and South America and the southern states of the USA. They have a mutualistic relationship with a fungus. The ants gain food from the fungus and the fungus gains a place to live protected by the ants from predators and parasites.

There are many different species of fungus-growing ants, but they all belong to the tribe Attini. The higher attines include the well-known leaf-cutter ants, while the lower attines are a less well studied group which tend to have small colonies and collect a variety of foods for their fungus. Several different species of fungus-growing ants are studied at the Universities of Copenhagen and Aarhus, representing both the lower and higher attines.

A colony of Atta, probably the best known of the leaf-cutter ants is shown below. Many of the same features are shown to a greater or lesser degree by the other fungus-growing ants. Click on the pictures or the text below to find out more.

1. Sections of leaves are cut from vegetation around the nest by specialised workers.
2. The leaf sections are carried away along trails.
3. The leaf sections are taken back into the ant nest, where they are given to another group of specialised workers that process the leaves.
4. The processing workers reduce the leaf fragments to a mulch which is used to feed the ant colony's fungus garden. The fungus feeds on the mulch and uses the nutrients to grow. It also produces special structures called gongylidia which are fed on by the ants.
5. The queen sits among the fungus garden laying her eggs. When the eggs hatch, the larvae that emerge will eat the gongylidia while they are being cared for by specialised nurse workers.
6. When the nutrients have been removed from the leaf material, the waste is transported to special dump chambers, where dead ants and dead fungus are also placed.