How tough is a mosquito?

To answer this question, we must look at the popular axiom: Newton's Third Law of Motion. This law states that whenever one object exerts a force on a second object, the second exerts an equal and opposite force on the first. So basically for every action, there is a reaction.

When you swat a fly in mid-air, the fly will die if the swatter surface hits the fly due to the initial force you exerted using your arm to swing the swatter. This is enough force to kill the insect (either damage its wings or whatever). Sometimes, however, you're mislead to think that the fly can survive these blows; this is because the wind generated by the surface area of the swatter moving through the air pushes the fly out of the way. Even a minute amount of air is enough to push the little insect out of the way from destruction.