Monday, 31 October 2011

Spot the frippet: bat.

We're well into autumn here in England, but there should still be a few bats about to add some romance to Halloween, even if they're made of rubber.

Bats are so incredible that I'd need a whole book to list all their wonders, but did you know:

That some bats scream four hundred times a second and use the echoes of the screaming to stop themselves bumping into things in the dark?

That a bat the size of a mouse can make a noise as loud as an express train (though the sound is so high that humans, luckily, can't hear it)?

That the bat can't hear it either, because to stop itself deafening  itself it dislocates its ear drums four hundred times a second, too -and then reconnects them in time to hear the echoes of its screams.

That there are other bats which emit one long constant scream, and their way of avoiding making themselves deaf is to scream at a particular pitch they can't hear, and then rely on the Doppler effect* to change the pitch of the echo so they can hear it.

As I say, I could go on forever, but I'll leave you with something sweet:



Enjoy Halloween!

Spot the frippet: bat. In the 14th century this word was bakke. It probably comes from Scandinavia, as there's a lovely Old Norse word ledhrblaka, leather-flapper, and a Swedish dialect word natt-batta, night bat.
*The Doppler effect is what's going on when you hear the pitch of a siren or an engine change when it switches from travelling towards you to travelling away fom you.

2 comments:

  1. I am bowled over by this stuff. It is more than amazing, it's mind-boggling and completely defies reason and everything one has learned about the world. Marvellous stuff. Still, I'd rather read about them than have them fly about my house, which happened on a regular basis at twilight when we lived in Northern Nigeria, many decades ago. We used to have to retire early under the mosquito nets!!

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  2. Mosquito nets to keep away bats is as pleasingly bizarre as bat-flapping nets to catch sparrows. These were used in Hertfordshire at the beginning of the 20th century.
    I'm afraid the sparrows ended up in pies.

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