This August brings with it much memorializing, as it marks the 70th anniversary of the beginning of the end of the Pacific War, the last conflict of World War II. This end began of course with the cataclysmic use of 
the most extraordinary weapon humanity had seen to date: the atom bomb. The city of Hiroshima saw widespread destruction when the United States unleashed the bomb “Little Boy” at 8:15am on August 6, 1945; “Fat Man” was dropped on Nagasaki on the morning of August 9. Japan formally surrendered on September 2.
While scholars are now, with the benefit of hindsight, divided on the necessity of using the A-bomb, at the time decision was regarded as inevitable, and taken very seriously (Harry S. Truman called it “an awful responsibility.”) In fact, during the long march into the Atomic Age, many other ideas were floated by Americans intent on breaking Japan. One of the nuttiest involved everyone’s favourite rabies vector, bats.
In January 1942, Dr. Lytle S. Adams of Pennsylvania penned a missive to President Franklin Delano Roosevelt, outlining his plan to arm bats with incendiary bombs, and take advantage of their natural tendency to fly in a wide spread and roost in eaves to destroy the wood and paper homes of the Japanese people over whom these special bats would be dropped.
This plan, dubbed “Project X-Ray,” was perhaps crazy, but so well-elucidated (and Adams so well-connected: he was a friend of Mrs. Eleanor Roosevelt), that FDR kicked it up to the head of wartime intelligence, Col. William J. Donovan. Dr. Adams and his off-the-wall scheme got funded.
Adams footed a team of bat experts who sourced agreeable chiropterans from a Texas colony of Mexican Free-Tailed bats. Then thought turned to the nature of the bombs, both the ones the bats would be carrying, and the one in which they would be dropped from a plane. From i09:
“Two major tasks remained: designing the mini-bombs that each bat would carry, and the larger bomb that would house the whole shebang. The first problem was given to Dr. Louis Fieser, best known as the inventor of military napalm. It was a tricky project—the bombs had to be light enough for the bats to carry, and they couldn’t contain reagents, like phosphorus, that reacted with oxygen, because their bat carriers had to be able to breathe. Fieser settled on a light pill-shaped case made out of nitrocellulose, or guncotton, and filled with kerosene. A capsule on the side of the bomb held a firing pin, which was separated from the cartridge by a thin steel wire. The whole thing weighed seventeen grams (or about as much as three American quarters), and dangled from a string.”
“The larger, housing bomb was entrusted to the Crosby Research Foundation, a joint venture of famous crooner Bing Crosby and his brothers Bob and Larry [Ed. note: What?!]. Based on a design by Adams, it looked, from the outside, like a normal bomb, a cigar of sheet metal with a tapered nose and fins. But on the inside, it was outfitted with a parachute and heating and cooling controls, and stacked with enough cardboard trays to hold one thousand and forty bats.”
The bats would be prompted to hibernate by the cool interior temperature of the bomb. They would then slumber through the long flight to their target city, bearing mini bombs strapped to them, into which copper chloride, a corrosive, had been injected. Once released, they would awaken and scatter, hiding in the roofs of the structures that they found. And when night fell, they would instinctively chew through the strings holding the bombs to their bodies, and fly off in search of insect breakfast. (I was very happy to learn they were not intended to blow up too!) The copper chloride would then finally reach the steel firing pin, causing it to release, and the mini incendiary bombs to leap into flame. And the city – and any city they chose to rain bats on – would burn to the ground.
It wasn’t hubris or impracticality that ended up killing Project X-Ray, which saw continuous development for two years: it was the military’s need to push all available resources to the Manhattan Project. So we have no way of knowing how effective Dr. Adams’ batty plan would have been, though he maintained to the end that it would have been just as destructive as Fat Man and Little Boy’s combined efforts, with far less loss of life.