The ancient Romans used bees and hornets’ nests as weapons of war. The nests were placed inside breakable clay urns and then catapulted onto the decks of enemy ships. During sieges, the Romans drilled down vertically into the tunnels their enemies were digging and dropped furious hornets and other stinging creatures into their midst.

During medieval sieges, defenders of a walled town did the same thing—they tossed nests into the midst of their besieging enemies, sending them scattering.

Source: Adrienne Major, Greek Fire, Poison Arrows, and Scorpion Bombs