The House Fly: An Expert Pilot

House flies have notoriously short lives, but are born with expert flight and evasion techniques. So while they may “drop like a fly”, they also fly like a fighter ace. In a new study published in the journal Science, April 10, some of the fly’s secrets of evasion have been revealed.

The study was held at the University of Washington’s Dickinson Lab, Seattle. The research team used high speed cameras, able to take up to 7,500 frames per second, to capture the movement of flies. With the high speed images and study techniques, new insight has come into the field of insect research.

For centuries the speed of the fly has been a challenge for humankind. Capturing a fly is symbolic of a quick mind, most commonly used in films or novels to show just how cool the “cool guy” is. Who could forget the scene in Karate Kid where Miyagi Sensei catches a fly with his chopsticks? Spies, ninjas, and warriors are all commonly depicted with this fly-catching ability. For the common Joe, however, fly swatting is a persistent annoyance.

A fly veers to avoid objects quicker than we blink. The research team found that flies perform a banking maneuver to redirect their velocity. A fruit fly can enter rotations of 90 degrees or more with incredible control. “Based on the direction of the looming threat—whether from the back, the front, or the side—the flies perform a different type of escape maneuver that is very controlled,” said co-author Florian Muijres. It was previously thought that a fly would do a “yawing” rotation around a vertical axis.

“Airplanes, helicopters, and other insects bank to direct their aerodynamic force vector into a turn, so the fact that fruit flies do so too isn’t really a surprise,” Muijres said. But was is a surprise is the sheer speed on which they do it. It’s been suggested that these flies have a neuron dedicated to emergency maneuvers running down the body to the wings and muscles. Further research is needed to prove the theory. Understanding the way flies maneuver could help to engineer robotics to avoid obstacles.

In the meantime Muijres does have a suggestion to ease our swatting woes. Swat from the fly’s side. The fly will maneuver away, flying straight away from your hand, “so if you keep your hand going in the same direction, you can catch the fly.”