Leafcutter ant

Farming 50 million years before humans

Leafcutter ants cut leaves and carry them to their nest — but don't eat them! They chew the leaves and grow a fungus on them, which they eat. So they're farmers — millions of years before humans! One nest holds 8 million ants. Each ant carries a leaf 50 times its weight — like you lifting a car.

Leafcutter ants (Atta, Acromyrmex — 47 species) are the fungus-farming ants of Central and South America, which 'invented' agriculture 50 million years ago. They carry leaf pieces to the nest, chew them and grow a garden of Leucoagaricus fungus on them — the colony's only food; bacteria on their bodies produce antibiotics against invading mould. Castes: the queen (15 years, 30,000 eggs a day), soldiers, medium workers (cutters and carriers) and tiny workers (gardeners and 'hitchhikers' who ride on leaves to fend off parasitic flies). A nest holds 8 million ants and extends 30 m² deep with a ventilation system; they are the largest herbivores of the tropics, consuming 17% of leaf biomass.

Fun facts

• Ants took up farming 50 million years ago — humans only 10,000.
• Ants 'make' antibiotics — bacteria on their bodies protect the fungus.
• Tiny ants 'ride' on the leaves — to chase off flies.