Echolocation allows creatures to move around in pitch darkness, so they can navigate, hunt, identify friends and enemies, and avoid obstacles. Bats are not the only species that uses echolocation. For dolphins and toothed whales, this technique enables them to see in muddy waters or dark ocean depths, and may even have evolved so that they can chase squid and other deep-diving species. Another intriguing possibility is humans – many blind people can find their way around simply by listening to echoes bouncing off surrounding objects. Scientists have been experimenting to see if humans can use technology to emulate nature’s use of ultrasonic sound to create assistive devices for the blind.

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