Part of the show How We Hear, Echolocation and Giant Whoopee Cushions
Steve in Dorset asked:
If all these bats are whizzing about and making all these noises, how do they not fly into each other? How do they know who's noise is who's?
They're all tuned to different frequencies, but only very slightly different frequencies. Some of them will be tuned to 61.45 kHz, others will be tuned to 61.44 kHz and so forth. Because their ears are so narrowly tuned, they can pick up these very narrow echoes that come back. So they're very specifically only hearing their own noises coming back.