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The Debunker: How Blind Is A Bat, Anyway?

by Ken Jennings

The poet John Keats called autumn a “season of mists and mellow fruitfulness.” Let’s leave the “mellow fruitfulness” for November - October is all about the season of mists. We’ve asked Jeopardy! smart-aleck Ken Jennings to fact-check the spookiest Halloween lore he could dig up and fill us in on all these monstrous misconceptions.

Spooky Myth #3: Bats Are Blind.

Bats do have amazing ways of getting around that have nothing to do with eyesight, as you probably know. One suborder of bats, the microchiropterans, can echolocate, which means they emit high-pitched squeaks and listen for the sound bouncing back to help navigate and detect tasty nearby bugs. But echolocation wasn’t discovered until 1938, so it has nothing to do with the popular saying “blind as a bat,” which goes back to Shakespeare’s day. Maybe the cliché originally derived from the confused flailing of bats trapped indoors, or from the assumption that a nocturnal animal like a bat would be, in Bruce Springsteen’s words, blinded by the light.

But that’s not true at all—no bat species is close to blind and, in fact, most of them have pretty great vision. Fruit bats have large eyes and well-developed visual centers in their brains, and most have color vision. Smaller bats, which rely less on eyesight due to their sonar superpowers, were long thought to be pretty helpless in daylight, but new research shows that’s not true. These bats have both rod and cone cells in their retinas, and can therefore navigate well by day or night. In fact, a 2009 experiment by German zoologists showed that some bats can even see ultraviolet light, which helps them get around in dim twilight and find flowers with the most promising nectar.

So in a fairer world, bats would be popular symbols of accurate, versatile vision. “That person is as ably sighted as a bat!” an impressed DMV employee might say. A more accurate simile would be “blind as a subterranean mole rats,” since those rodents are one of the few complete blind mammals. But I’ll admit that would take a lot longer to say.

Quick Quiz: The largest genus of bat is often given what name, even though they’re unrelated to the canids in question?

Ken Jennings is the author of Brainiac, Ken Jennings's Trivia Almanac, and Maphead. He's also the proud owner of an underwhelming Bag o' Crap. Follow him at or on Twitter as @KenJennings.

Photo by Flickr member mrdorkesq. Used under a Creative Commons License.