Research

Flies Don't Think Much Of Turning

DBIS

Examining the amazing flight abilities of the common fly.

Apr 2, 2010

Originally published: Feb 3, 2012

By Devin Powell
Inside Science News Service

WASHINGTON (ISNS) -- The next time a fly dodges your swatter, take a moment to appreciate how maneuverable these little pests are. Fruit flies can make a complete U-turn in one-tenth of the time it takes you to blink.

"That's faster than your eye would be able to perceive," said Attila Bergou of Brown University in Providence, R.I. "It's something that manmade machines can't currently reproduce."

This aerial stunt requires surprisingly little thought on their part, according to experiments conducted by Bergou and colleagues at Cornell University in Ithaca, N.Y.

Related Video: Watch The Turn

For years, scientists have known that a fly moving in a straight line synchronizes the movements of its wings. The flies bounce up and down, back and forth with a rowing motion that creates eddies of air, keeping the insect aloft.

But researchers have puzzled over how a fly's simple brain can precisely control each of the 250 wing flaps per second it makes to execute a 180 degree turn.

"Imagine flapping your arms 250 times per second," said Bergou. "You're going to have a really tough time controlling the orientation of your arms."

Using a high speed camera filming at 8,000 frames per second and new image tracking software, Bergou discovered that flies rely less on their brains than previously thought and more on the clever design of their wings. To make a turn, a fly simply twitches a muscle that rolls its shoulder slightly. The wing does the rest, naturally adjusting over the course of a few beats, tilting by about 9 degrees, and creating drag forces that wheel the insect around.

This design principle behind fly U-turns -- wings that are self-adjusting and do the work of turning by themselves -- has attracted the interest of researchers like Robert Wood of Harvard University, who are developing the latest generation of tiny manmade flying machines that buzz not with life but with electricity.

Inside Science Television Copyright Notice and Terms of Use

Inside Science Television content is protected by copyright and other intellectual property laws. We welcome links, including HTML-embedded ones, to Inside Science Television content and webpages as long as the links do not state or suggest any sponsorship or endorsement of your site by Inside Science or the American Institute of Physics.

Pursuant to the copyright and trademark laws of the United States, you agree:

• Not to reproduce, distribute, modify, re-post on another site, or sell any Inside Science Television content without specific written authorization from the American Institute of Physics or the appropriate copyright owner.
• To maintain any and all copyright or other proprietary notices embedded in or attached to any content.
• To refrain from framing, inline linking, or mirroring any portion of Inside Science Television content or websites.

© 2012 American Institute of Physics. All rights reserved.