Echolocation is for bat what vision is for people, the basic way to get the perception of the world. What looks like a simple principle of transmitters and receptors, is actually a complex system of sound transmission of different signals and receiving an echo of the same. Echolocation sounds have many characteristics that differ between families, and sometimes even between individuals of the same species. Thanks to this, determination of the species is possible by reading echolocation sounds. For those purposes they can alter frequency and/or intensity of the ultrasound signals. Bats use echolocation for orientation in space, catching the prey or to communicate with other individuals. The entire morphology of the bat's head is based on producing better echolocation signal. Precisely for this reason there are various physical extras that allow bat a better production and sound focusing. Bats use other senses as well, such as smell, when hunting prey, but echolocation gives them the necessary precision. Echolocation calls are mostly high-frequency signals, and thus silent to people. This is why people initially thought that the bats were quiet animals, but today we know that they produce very loud sounds while echolocating. These sounds are very flexible, and bats can modulate them depending on the foraging area. Thus, we can distinguish species that forage in open spaces from those who hunt along the edge of the forest or in the middle of dense vegetation.