Leafcutter Ants: Tiny Farmers of the Rainforest
1Walk through a rainforest in Central or South America, and you might see a line of green leaf pieces moving across the ground. Look closer, and you will find an ant under each piece. These are leafcutter ants. They are not just carrying snacks home. Leafcutter ants are farmers that grow their own food.
2Worker ants climb plants and use their sharp jaws to cut out pieces of leaves. Then they carry the pieces back to their nest, often holding them high over their heads. A piece of leaf can be much bigger than the ant carrying it. The ants follow a trail that leads them home, sometimes from far away.
3Surprisingly, the ants do not eat the leaves. Inside the nest, other workers chew the leaf pieces into a soft, wet paste. They spread this paste in underground rooms. A fungus grows on the paste, a little like mold growing on old bread. The fungus is the ants' food. The ants care for their fungus garden every day. They add fresh leaf paste, and they remove pieces that are old or spoiled.
4A leafcutter colony works as a team, and its ants come in different sizes. Each size has its own jobs. The biggest ants guard the nest. Middle-sized ants cut and carry leaves. The tiniest ants tend the fungus garden. Some of them even ride on top of leaf pieces as the bigger ants carry them home. Scientists think these riders help protect the carriers from tiny flies that attack them.
5A large colony can hold millions of ants, and their nest may stretch deep under the ground. All of those ants depend on the fungus, and the fungus depends on the ants to feed it. By cutting, carrying and gardening, leafcutter ants grow enough food for their whole colony.