Fruit flies use their eyes to control flight at incredible speeds

Fruit flies use eye movements to control their flight with a reaction speed that is about 30 times faster than the blink of a human eye. With a new understanding of this incredible ability, scientists at Penn State will apply the rapid flight control techniques of fruit flies to the field of mechanical engineering. 

“If you are able to study flies doing what they do best – flying – you can find some incredible engineering solutions that already exist in biology,” said study first author and doctoral student Benjamin Cellini.

Professor Jean-Michel Mongeau, director of the Bio-Motion Systems Lab, worked with Cellini to determine how fruit flies use eye movements to quickly coordinate their wings in response to what they are seeing. 

Even though our eyes are not on the back of our head like flies, humans can also execute a stabilizing gaze in which we zero in on a target with our eyes.

“But that is a challenging, complex problem to understand, how are we and other animals able to do that so well?” said Professor Mongeau. “My lab is interested in active sensing, which is a branch of engineering and biology that studies how sensor movement, like eyes scanning a room, can enhance sensing itself.”

According to the researchers, understanding how animals like flies use active eye movements to control flight could greatly enhance robotics. 

Most robots have stationary sensors, which means sensing and movement are not interconnected. The flight control of robots has great potential for improvement if the efforts of visual sensors could be coordinated.

The team’s investigation revealed that the eyes of the fruit fly were able to react four times faster than its body or wings. These reactions were strongly associated, which confirms that flies rely heavily upon eye movements to coordinate their wing movements.

“We’ve shown that their eyes can control and stabilize their vision better than we originally thought, by reducing motion blur,” said Cellini. “Like in sports, they teach baseball players to follow the ball with their eyes to reduce blur and increase batting performance.”

Professor Mongeau said one of the most significant findings is that fly eyes slow down visual motion signals to the brain to enhance their flying behavior.

The researchers believe unlocking the secrets of the biological world could have broad implications for technology.

“In engineering, you are taught to apply principles from mathematics and physics to solve problems,” said Cellini. “If you want to build a robot to fly on Mars, you can use engineering concepts to provide potential solutions. But we don’t always have to develop ideas from scratch; we can also seek inspiration from nature.”

The study is published in the journal Proceedings of the National Academy of Sciences.

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By Chrissy Sexton, Earth.com Staff Writer