During a thunderstorm, a mosquito would likely be hit about every 25 seconds. They obviously aren’t dodging raindrops, as appealing as the mental image may be.

So the researchers created a “flight arena” to study mosquito-raindrop collisions essentially a five centimeter wide, 20 centimeter tall rectangular mesh cage. In order to simulate raindrops falling at their terminal velocity (which would otherwise require a height of 10 meters) they shot a water jet point-blank into the cage of mosquitos.

To figure out what was happening during midair collisions, the authors shot a strong, 9m/s jet into the cage, and observed the impact with six mosquitos. In all of these collisions, the insects tumbled down the cage, getting hit repeatedly, before separating from the jet and landing on the side of the cage. This jet is actually stronger than terminal velocity raindrops, so this test shows that mosquitos would survive such an impact.

Confirming an earlier prediction, the team found that most drops impacted on the wings and legs, rather than the bodies—the body only makes up one-quarter of the potential impact area. This results in a quick, glancing blow that essentially rotates the insect (either pitch, yaw, or roll). The contact lasts a fraction of a second, after which the mosquito quickly recovers.

But direct hits to the body did happen. When rain falls on a stiff object, like a tree branch, the drops spread out very quickly. This rapid momentum transfer results in a strong impact force, roughly 10,000 times the weight of a mosquito. In other words, splat.

(Source: futurenow321)