Nomamyrmex army ants are among the few animals that successfully attack leafcutter ant nests. The leafcutters are not without their defenses. Here two Atta workers attack and kill a Nomamyrmex esenbeckii scout, preventing the army ants from discovering the leafcutter's trail. Gamboa, Panama

A soldier of Nomamyrmex esenbeckii, the most heavily armored of the army ants. As these ants are predators of the giant Atta leafcutting ants, they require stout, sturdy appendages to withstand the slicing mandibles of their prey. Gamboa, Panama

Nomamyrmex esenbeckii workers carrying a massive Pheidole pupa they have taken in a successful raid. Monte Verde, Minas Gerais, Brazil