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How do bats "see" with their ears in complete darkness?

Close your eyes. Imagine you're in the dark. Now say, "AW!" and listen to the sound bounce off the walls. Somewhere the echo will come back faster, somewhere else slower. If you're very, very careful, you'll know where the wall is and where the door is. That's how bats live—only a million times better!

A bat flies in complete darkness and emits tiny sound pulses: «click-click-click!» — up to 200 times per second. We don’t hear these sounds — they are too high-pitched for human ears. But the bat listens to how its clicks are reflected off everything around it: from the wall of a cave, from a leaf, from the wing of a butterfly. Over time, while the sound returns, the bat sees a picture of the world — as we see with our eyes.

And now the most amazing thing. A small night bat catches up to 3,000 mosquitoes in one night! It finds each one in the dark, at a speed of 30 km/h, in a forest where branches are everywhere. Scientists have measured: it distinguishes objects the thickness of a human hair - only by echo. Imagine: you run in a dark forest and go around every cobweb with your eyes closed!

Some bats even "scream" so loudly that it would deafen a human — 140 decibels, like a jet plane. But they cover their ears with tiny muscles during their screams so as not to go deaf themselves. Smart!

People have spied this trick in nature. Today, sailors use sonar, a system that works in the same way as a bat. And scientists are making devices for blind people that help them "hear" space. Thank you, little night friend!