Mosquitoes are extremely robust. They can survive being hit by raindrops 50 times their size. The insect is knocked down a little by the raindrop travelling at 300 times normal gravity, but it recovers and flies on.
This attribute was discovered by videoing insects actually being hit by raindrops from artificial rain. There was no improvement in stopping the spread of malaria. Better ways of designing tiny flying robots was enhanced, however, because rain tends to knock mechanical drones off course. Even aeroplanes are detrimentally affected by rain.
The raindrops on mosquitoes tests were exciting to watch. As the rain hit them they dropped, then recovered and sheltered on the wall of the test area. They fell an average of 13 body lengths. Nearly all hits were glancing blows which made mosquitoes roll, pitch and yaw. A direct hit led to a fall of 20 body lengths.
The theory is that mosquitoes are so small the speed of raindrops falling to earth is not affected, This means little energy is transferred to mosquitoes by collisions.