They are very small, and high up. As the AI gets better they will also become better at evading fire, just as mosquitoes are really hard to get. Try catching a

They are very small, and high up. As the AI gets better they will also become better at evading fire, just as mosquitoes are really hard to get. Try catching a cat that doesn't want to be caught. Equip the cat with an explosive warhead and make it a thousand cat swarm.