[AnotherUnixGeek]

The reason it's so hard to kill a mosquito is that they move really well.

That's why so many of us resort to spray insecticides. I'd guess an aerosol spray that could mess up the optics and gum up the flight capabilities of tiny drones would work about as well.

[Army Air Corps]

Portable EMP units. One can use the magnetron from an old Microwave oven...