The real story
Leafcutter ants don't eat leaves. They chew them into a mulch to grow a fungus, and the fungus produces little nutrient-packed swellings that feed the colony. In 2024 a Smithsonian-led study that traced the family trees of hundreds of ants and fungi dated the start of this partnership to about 66 million years ago. That was just after the asteroid impact, when dead plants and spreading fungi created the perfect conditions.
Their farms have pest control too. The fungus garden is threatened by a parasitic mould, so many leafcutters carry bacteria on their bodies that make antibiotics against it, and worker ants weed out anything foreign. A colony can reach about 8 million workers. When a new queen leaves to found her own nest, she carries a small piece of the family fungus in a pouch in her mouth to start a new garden.
