In Batesian mimicry, a harmless species imitates a more dangerous one in an evolutionary ‘ruse’ that affords the mimic protection from would-be predators. Now, researchers have discovered the first case of acoustic Batesian mimicry in mammals and one of very few documented in any species: greater mouse-eared bats imitate the buzzing sound of a stinging insect to discourage predatory owls from eating them.