Watch as it chases a moth. Listen to the difference in the signals as it approaches, and then catches, its prey. Now close your eyes and listen. Chances are you will know what the bat is doing merely by the repetition rate of its calls. Not all bat species will sound the same, and when you become proficient, you can often identify a species by the tone of its call, just as bird watchers identify birds by their songs.
Echolocation is clearly one of the most fascinating aspects of the biology and behavior of bats.
You will be richly rewarded. With the aid of a bat detector, a bat's ultrasonic echolocation calls become audible to the human ear. This sonogram illustrates the timing and sequence of calls produced by a big brown bat as it searchs for, detects, and attacks a flying June beetle. Each call starts at a higher frequency and sweeps to a lower one. The entire sequence lasts less than a half a second.