Bat bombs were an experimental World War II weapon developed by the United States. The bomb consisted of a bomb-shaped casing with over a thousand compartments, each containing a hibernating Mexican free-tailed bat with a small, timed incendiary bomb attached.
The bomb was designed to terrorize the people of Japan in a most unexpected way.
Dr. Lytle S. Adams, like most Americans at the time, was enraged by the attack on Pearl Harbor and had begun looking into what he could do to lend his support to the war efforts.
Having just returned from a vacation in New Mexico, he remembered being “tremendously impressed” by the Mexican Free-Tailed Bats, which migrated every year through the state and live primarily in Carlsbad Caverns.
After reading up on them, he returned to the caverns to capture some for himself. Upon studying them, Dr. Adams realized that they were perfectly suited for war.
After all, they were able to withstand high altitudes, fly long distances, and carry heavy loads — such as tiny timed bombs.
Like most Americans in the 30’s and 40’s, Adams image of Japan was a bit skewed. Most people believed Japan was an island of crowded cities “filled with paper-and-wood houses and factories.”.
With that train of thought, he believed that with enough bat bombs, the military could be wipe out entire cities simply by letting the bats do what they do best — migrate and hide in dark places.
So he did what any concerned citizen with a brilliant plan would do. He outlined his plan and sent it to the White House.
The proposal seemed like the plot of a B-horror movie. It promised to “frighten, demoralize and excite the prejudices of the Japanese Empire,” claiming that “the millions of bats that have for ages inhabited our belfries, tunnels and caverns were placed there by God to await this hour.”
Adams was clearly paranoid, noting that the plan “might easily be used against us if the secret is not carefully guarded. However, Adams was also very confident.
“As fantastic as you may regard the idea,” he said. “I am convinced that it will work.”
The proposal actually made it into to President Roosevelt’s hands (most likely due to Adams personal friendship with first lady Eleanor),
and he passed it along to his head of wartime intelligence Colonel William J. Donovan.
Roosevelt also included a letter of his own, backing up Adams preposterous theory.
“This man is not a nut,” he wrote. “It sounds like a perfectly wild idea, but is worth looking into.”
The proposal also found its way to Donald Griffin, who had pioneered research on bats’ echolocation strategies. Griffin lent his support to the plan in a letter.
“This proposal seems bizarre and visionary at first glance,” he wrote, “but extensive experience with experimental biology convinces the writer that if executed competently it would have every chance of success.”
After seeing Adams’ demonstration using the bats he had captured himself, the White House assembled a team and eventually agreed upon using the Mexican Free-Tailed bat. The U.S. Air Force then gave the authority for investigations to begin, and the plan became known as Project X-Ray.
Thousands of bats were captured across the southwest, tiny bombs were designed, and a transport method was engineered. However, a hitch in the plan was soon discovered, and after a minor setback where the Carlsbad Army Airfield Auxiliary Air Base and caught fire, the plan was scrapped.
The National Defense Research Committee (NDRC) observer stated: “It was concluded that X-Ray is an effective weapon.” The Chief Chemist’s report stated that, on a weight basis, X-Ray was more effective than the standard incendiary bombs in use at the time: “Expressed in another way, the regular bombs would give probably 167 to 400 fires per bomb load where X-Ray would give 3,625 to 4,748 fires.”
More tests were scheduled for the summer of 1944 but the program was cancelled by Fleet Admiral Ernest J. King when he heard that it would likely not be combat ready until mid-1945. By that time, it was estimated that $2 million had been spent on the project.
It is thought that development of the bat bomb was moving too slowly, and was overtaken in the race for a quick end to the war by the atomic bomb project.
Alas, the bat bomb was not meant to be, however gung-ho the entire White House seemed to be about it. Adams was disappointed. However, he would come up with a few more crazy schemes. Some of which include seed packet bombs and a fried chicken vending machine.