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Dear Selena:
Those who believe bats are blind just can't see the truth themselves. In reality, all bats can see.
Many of them, in fact, can see really well, even in dim light. Most fruit-eating bats, for example,
have large bulging eyes that help them find their way and locate food by sight. But other bats,
especially those that hunt for insects at night, need to rely a lot more on other senses in the
dark. These winged wonders make up for low visibility by "seeing" with their ears, and they do this
by using a technique called echolocation. A bat echolocates by sending out streams of high-pitched
sounds through its mouth or nose. These signals then bounce off nearby objects and send back
echoes. By "reading" these echoes with its super-sensitive ears, the bat can determine the
location, distance, size, texture and shape of an object in its environment. In some cases, a bat
can even use echoes to tell insects that are edible apart from those that aren't. And even bats
which have been blinded can catch their food without a hitch this way.
Curious about what bats sound like when they're echolocating? Sorry to say, but your ears
alone won't tell you. Those sounds are so high-pitched, they're beyond the range of human hearing.
But if you borrow a scientist's bat detector, a handy gadget that converts bat calls to sounds
people can hear, you can indeed listen in and make the mysterious world of bats a little less
mysterious.
Signed,
Wendell
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