Scientists reveal ants as fungus farmers

This photo shows the head of the defensive soldier caste of the leaf-cutting ant Atta laevigata, which lives in the savannahs of northern and central South America. The mature nests of Atta laevigata are huge, containing many millions of worker ants that forage across many acres of land. A colony of Atta laevigata can live for 20 years and weigh as much and consume as much grass as an adult cow. Photo by Eugenia Okonski/Smithsonian Institution