PASADENA, Calif. -- Ever wonder why those buzzing houseflies are so good at getting away when you're trying to swat them? Researchers at California Institute of Technology say they've solved the mystery, reported KNBC-TV in Los Angeles.

Using high-resolution, high-speed digital imaging of fruit flies (Drosophila melanogaster) faced with a looming swatter, professor of bioengineering, Dr. Michael Dickinson and graduate student Gwyneth Card determined the secret to a fly's evasive maneuvering.

Long before the fly leaps, its tiny brain calculates the location of the impending threat, comes up with an escape plan, and places its legs in an optimal position to hop out of the way in the opposite direction. All of this action takes place within about 100 milliseconds after the fly first spots the swatter.

"They're actually jumping away from our swatter because they take the time to plan their escape," Dickinson said. "This illustrates how rapidly the fly's brain can process sensory information into an appropriate motor response."

"We also found that when the fly makes planning movements prior to takeoff, it takes into account its body position at the time it first sees the threat," Dickinson said.

"When it first notices an approaching threat, a fly's body might be in any sort of posture depending on what it was doing at the time, like grooming, feeding, walking, or courting. Our experiments showed that the fly somehow knows whether it needs to make large or small postural changes to reach the correct preflight posture. This means that the fly must integrate visual information from its eyes, which tell it where the threat is approaching from, with mechanosensory information from its legs, which tells it how to move to reach the proper preflight pose," Dickinson said.

The results offer new insight into the fly nervous system, and suggest that within the fly brain there is a map in which the position of the looming threat "is transformed into an appropriate pattern of leg and body motion prior to take off," Dickinson said.

"This is a rather sophisticated sensory-to-motor transformation and the search is on to find the place in the brain where this happens," Dickinson said. "There's actually many labs around the world trying to figure out how their little brains work so we can use that knowledge to figure out how our own brains work."

Dickinson told KNBC that he's been in science almost 20 years and he's never published anything that has received so much public attention.

The paper, "Visually Mediated Motor Planning in the Escape Response of Drosophila," was published Aug. 28 in the journal Current Biology.

The research was funded by the National Institutes of Health and the National Science Foundation.