Q. The bats can fly in the dark because__:
Answer: they generate ultrasonic sound waves
Notes: Bats use echolocation to navigate and forage, often in total darkness. They generally emerge from their roosts in caves, attics, or trees at dusk and hunt for insects in dark at night. The use of echolocation allows them to occupy a niche where there are often many insects (that come out at night since there are fewer predators then) and where there is less competition for food. Bats emit sound of frequency 20KHz to 100KHz. Their sounds are reflected in the environment, hitting various objects and returning to the bat as echoes. The echo signals enables the bat to form a mental map of its surrounding.