Bats are small flying mammals that belong to the large family of bats, that alone today contains between 1000 and 1200 species worldwide. The most common is the Pipistrelle. These nocturnal animals are mostly insectivorous, with the exception of larger species that may be carnivorous, and thus feed on small flying insects. To hunt they use ultrasound they emit either by the mouth or by the nostrils and which return to the ears.