The Natterer's bat is a nocturnal insect-eater, hunting only after sunset and throughout the night. It tracks down small, flying insects ,such as moths, by its echo-location system, similar to the radar-scanning equipment used by aircraft and ships. A special fleshy spike, known as a tragus, in each ear is part of its sound-reception system. This special 'radar' also keeps them from bumping into objects in the dark!
Insects are usually captured in mid-flight, but sometimes the bats will pick insects off leaves.