Why don't mosquitoes get squashed by raindrops? Scientists find an answer.
A mosquito getting hit by a raindrop is equivalent to a human getting hit by a car, but the insects have evolved a way to roll with it.
A mosquito getting hit by a raindrop is the equivalent of a human getting hit by a car. But new research finds that these bloodsucking insects have no trouble absorbing the blow.Skip to next paragraph
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Mosquitoes weigh so little that raindrops don't splash on them, researchers report Monday (June 4) in the journal Proceedings of the National Academy of Sciences. Instead, mosquitoes get stuck to the drops, tumbling up to 20 times the length of their bodies before freeing themselves and flying off, unharmed.
"The drop comes at the speed of a comet, and instead of the mosquito resisting the force applied by the drop, it basically gets adhered to the drop like a stowaway," study leader David Hu, a professor of mechanical engineering and biology at Georgia Tech, told LiveScience.
"By doing this, the mosquito really minimizes the force that gets applied by the drop," Hu said. [Gallery: Drop-Dodging Mosquitoes]
Mosquitoes' uncanny ability to survive rainstorms may be key to their survival in humid climates. It may also be key to engineering tiny robotic flying machines that can withstand outdoor environments, Hu said.
No one had researched how these flying robots might survive rain, nor had anyone studied how living insects do so, Hu said. So he and his colleagues engineered an experiment to "smart bomb" mosquitoes with water droplets to see how they'd respond. They put mosquitoes in mesh cages, which vibrated every few seconds to prevent the mosquitoes from landing. They then dropped water on the insects with the same forces that would be present in a rainstorm.
Though raindrops are up to 50 times the weight of a mosquito, it was immediately clear that collisions were not fatal. Glancing blows sent mosquitoes spinning in the air, but they soon recovered. Direct hits resulted in the mosquitoes and water drops falling together before the insects got free and continued their flight.