Atta ants, commonly known as leaf cutter ants, are a remarkable species found primarily in Central and South America. These industrious insects belong to the order Hymenoptera, family Formicidae, subfamily Myrmicinae, genus Atta, and encompass several species. Known for their unique behavior of cutting and transporting leaves, Atta ants play a crucial role in their ecosystems.

Atta ants are equipped with mandibles that, thanks to a specific configuration of zinc atoms, possess cutting power comparable to a surgeon’s scalpel. However, as these ants age, their mandibles become dull, necessitating a shift in roles from cutting to carrying leaves.

Interestingly, they alternate their cutting direction annually to allow the forest to regenerate. In a single day, they can strip a tree of its leaves. Once the leaves are cut into small pieces, workers transport them to the nest. Their intensive harvesting is so significant that Atta ants are responsible for the degradation of one-quarter of all leaves in Central and South America.

Polymorphism, the occurrence of different forms among members of the same species, is a defining characteristic of Atta ants. The workers exhibit a range of sizes and shapes, with up to 10-20 distinct forms. The smallest workers, known as minims, tend to the fungus garden, while medium-sized workers, or mediae, cut and transport leaves. The largest workers, called majors, are responsible for defense. Minims also play a role in cleaning leaves of parasites before they enter the nest.

Atta ants are highly organized, even in their waste management. They create designated trash piles where they dispose of refuse and stash dead ants. This organization helps maintain the hygiene and health of the colony. They regulate the temperature within the nest thanks to intelligent waste pile structures. 

When a young queen leaves to establish a new colony, she carries a piece of the fungus in her social stomach. This fungus is passed down from generation to generation, potentially being the same strain cultivated by their ancestors millions of years ago. This continuity ensures the survival and success of new colonies.

Leafcutters are known in South America for the rapid defoliation of trees. As a snack, they are appreciated in Brazil and Mexico for their taste. But they lack the recognition as creators: in fact, their abandoned nests allow the roots of plants to grow easily through the empty tunnels. They are an essential cog in the wheel of forest biodiversity. So next time you spot a leaf-cutter ant, remember: behind that tiny creature lies a world of different skills, cooperation, and survival.