When Texas joined the Confederacy in 1861 she brought her bats with her. That may not seem like such a grand thing unless you know a thing or two about bats.
For one thing, they congregate. The Mexican Free-tail bats of Texas have been residing in the same Hill Country caves for hundreds of years.
Also, bats have a very simple sanitation system. It's called gravity. Time plus digestion and gravity is a formula that has yielded millions on pounds of bat waste on Texas cave floors. It's called guano and the Confederates were glad to have it.
See, you need three things to make gunpowder: sulpher, charcoal and saltpeter. Men of knowledge could extract saltpeter (potassium nitrate) from the bat guano.
Pretty soon Yankees were running from the Rebels' bat propelled lead.
A Mexican Free-tail Bat
Mining guano from Texas caves didn't end with the Civil War. Guano has other uses. During the 1870s the Texas Guano Company was shipping ten tons a day out of the Port of Galveston to Scotland. Scotsmen were using Texas guano to produce ammonia on an industrial scale.
By the time World War II came along though, firearms were using smokeless powder, which is a mostly guano-free formulation.
But the Army was still interested in the contents of Texas caves, only this time it was the bats themselves. A dentist named Lytle S. Adams had an idea and President Roosevelt liked it. The Army called it Project X-Ray.
Doc Adams plan was to fit millions of Texas bats with tiny incendiary devices and drop them over Japan. The devices had long delays. The idea was that the bats would seek out the darkest and most inaccessible areas of Japanese cities and then catch fire. Japanese cities back then were the most flammable in the world, being mostly made of wood and paper.
Marines were posted at cave entrances to guard these valuable assets.
Alas, it didn't work like Doc Adams hoped it would. Tests showed that many bats couldn't fly with the devices. They just hit the ground.
The project was canceled after one ill fated test in New Mexico. The bats incinerated an auxillary air base. They also destroyed a general's car when they roosted beneath the fuel tank.