What Is Echolocation and How Does It Work?
If you know anything about how sonar works, you have an idea of how bats use echolocation. Bats can contract their voice boxes to produce very high-pitched sounds. In most cases, the sounds are so high that they are ultrasonic, meaning that they are above the normal hearing range for a human. The human ear can perceive sounds up to 20,000 Hertz. Some bat calls on the low end of the spectrum are only 15,000 Hertz, meaning that they are within a human's normal hearing range. However, bat calls can reach frequencies of up to 150,000 Hertz, meaning that they are too high for humans to hear. When a bat emits calls, the sound waves bounce off objects in the air, such as insects that the bat uses for food. The reflected sound waves come back to the bat in the form of an echo. Bat species have different call patterns, and each individual bat has its own distinctive call. A bat's ears are finely tuned to recognize its own reflected sound waves. In fact, the entire morphology of a bat's face is designed for optimal echolocation reception. As a result, a bat can tell the size of an object and its distance from the reflected sound. Bats make intermittent calls when searching for food. Once they locate it, they can produce a series of pulses in short succession called a feeding buzz. This allows them to pinpoint the prey's exact location so they can find and catch it. Echolocation also helps bats to navigate in the dark by identifying obstacles in their path. Bats also use it to communicate with one another, and the calls used for socializing are different from those used to find food or for navigation.