Scientists at the MPI for Ornithology investigate echolocation and sensory performance in bats. Coexisting bat species often differ in sensory abilities, thus find different prey and reduce interspecific competition for food. It is difficult to detect insects in vegetation by echolocation. Bats rely on the faint rustling sounds of their prey in such a situation and hence run into trouble when exposed to background noise from a wind-moved reed bed or a highway. Bats also eavesdrop to find new tree roosts; conspecifcs’ calls help out.