Impact crater is a type of impact landform formed due to collision of astronomical objects. Impact crater is a circular depression formed by the hypervelocity impact of a smaller body. Impact craters should not be confused with landforms like sinkholes, glacial cirques which are different in composition and origin from the impact crater.
Bats use SONAR (Sound Navigation & Ranging).Sonar is a technique that uses sound propagation to navigate, communicate with or detect objects on or under the surface of the water, such as other vessels.