Insects are unique among all creatures. They are small relative to mammals. They are dangerous. some bite, some sting, and many transmit deadly diseases. Many governments have tried to weaponized them. They are in constant supply. For now, though, they are difficult to breed in large enough numbers to be used in warfare.

That doesn't mean that it can't happen one day. The military already has trained honey bees to sniff out bombs. During the civil war, insects were responsible for more deaths than war-related injuries by transmitting typhoid fever, louse-borne typhus, malaria, and yellow fever. We douse them deadly poisons, we sterilize them, we squish them, we swat them, yet the harder we try to control them, they never seem to disappear.