Bat bombs

No, I'm not making this up. During WWII, the US military actually considered using bats to carry tiny incindiary devices into Japan's major cities. The bats would then, of course, roost in highly flammable places where the incindiary devices would ignite fires and reduce Japanese cities to ashes, thus ending the war in the Pacific. That was the plan, and the military proved that it worked -- they accidentally burned down an air base in New Mexico (pictured at left) during the research and development phase.

The plan was never implemented, however. It seems there was another project in the works at the same time -- the atom bomb -- which was finally designated the weapon of choice for ending the war, thereby saving million of bat lives, though of course, at a tremendous human cost.

Reference: Bat Bomb: World WarII's Other Secret Weapon by Jack Couffer