Greater mouse-eared bat  (Myotis myotis)

Echolocation: detecting objects by reflected sound. Used for orientation and detecting and locating prey by bats and cetacea (whales and dolphins).
Polygamous: mating with more than one partner in the same season.
Tragus: a soft cartilaginous projection extending in front of the external opening of the ear. In bats it is thought to aid in the location of prey by generating many echoes, but the precise way in which this works is unknown.