Family Vespertilionidae, also known as evening bats or common bats, are the largest and best-known family of bats. Over three hundred species are distributed all over the world, on every continent except Antarctica.  Almost all vesper bats are insectivores, but some eat fish, and one species eats birds.  They rely mainly on echolocation, but they lack the enlarged noses that some microbats have to improve the ultrasound beam, and instead "shout" through their open mouths to project their ultrasound beams. In compensation, many species have relatively large ears.