All bats in subclass Microchiorptera and only one genera in subclass Megachiroptera have developed complex system for echolocation through the evolution. Echolocation is used for catching their prey, for and for communication and navigation. Bats in subclass Microchiroptera generate echolocation calls in very short pulses with high frequency. Calls generated in glottis in larynx are then emitted through their mouths or through nose which are modulated especially for that purpose. Low intensity echoes are registered by all bats with very sensitive auricular system. In their auricular system bats have developed special way of protecting auditory organs from high frequency calls they emit. At the time of generating echolocation calls stapes is removed away from oval window in auditory system. After generating calls it is returned back on its original place and the bat can hear echoes between echolocation pulses. The echo is converted into electrical impulses which than travel along auricular nerve all the way to the middle brain. After being preprocessed, impulses continue to travel into the auditory cortex for the final analysis.