Pseudonocardia are part of a family of bacteria that make antibiotics. People use antibiotics from these bacteria¬—and so do ants. Leaf-cutter ants farm fungus by feeding it leaves. But a pest called Escovopsis attacks the crops. Luckily, Pseudonocardia grow in the ants’ bodies. Antibiotics from the bacteria stop the pest. This keeps the ants’ food safe.