For a mosquito in flight dodging a barrage of raindrops up to 50 times its own body weight, less is best.
According to a study published today in the Proceedings of the National Academy of Sciences1 a mosquito’s key defence when struck by a plummeting drop is its tiny mass. Researchers say the findings could one day help to improve the durability of ‘micro-airborne vehicles’, insect-sized flying robots developed for applications such as surveillance or rescue operations.
The match-up between a mosquito and a raindrop is decidedly uneven. Mosquitoes are typically 3 millimetres long, and they weigh about 2 milligrams. At 2-8 millimetres in diameter, raindrops are similar in size to mosquitoes, but they can weigh up to 100 milligrams and plunge through the air at speeds of up to 9 metres per second. So to a avoid a knockout punch, mosquitoes have evolved a zen-like ability to become one with the drop.
“It’s like getting into a boxing match with a balloon, it just goes with the punch. Mosquitoes just move along with raindrops,” says team leader David Hu, who studies biolocomotion at the Georgia Institute of Technology in Atlanta. “It’s their [low] mass that makes this possible.”