This WWII Plan Consisted of Incinerating Japan With Bats Bearing Tiny Bombs
This WWII Plan Consisted of Incinerating Japan With Bats Bearing Tiny Bombs

This WWII Plan Consisted of Incinerating Japan With Bats Bearing Tiny Bombs

Khalid Elhassan - December 12, 2018

During World War II, a Pennsylvania dentist named Lytle S. Adams had an outside-the-box-thinking brainstorm: incinerate Japanese cities with tiny incendiary bombs attached to bats. Although the concept sounds batty, once people got over the fits of chuckles and thought of it seriously, it turned out to have some logical legs to stand upon. So a project was set up to test the effectiveness of Bat Bombs as weapons of war. It turned out to be a viable idea that might have actually worked, had the project been supported through the research and development phase, and then deployed.

As things panned out, the weapon did not make it out of R&D, and the project was shelved, with the Bat Bomb never getting deployed and put to the ultimate test. Thus, there there is no way to tell just how effective it might have been in real life combat. Still, how different would history and our world be if the iconic image of WWII’s end and the start of our current era had not been atomic bombs and mushroom clouds, but clouds of bomb bearing bats?

Birth of the Bat Bomb

Like many Americans, Pennsylvania dentist Lytle S. Adams was mad as hell when he first heard of the Japanese attack upon Pearl Harbor, and like many of his countrymen, he fantasized about payback. In his case, he got to thinking about what was then commonly known about Japanese cities: that most of their houses were flimsy wooden constructs. Wouldn’t it be grand, he thought, if somebody could take advantage of that?

This WWII Plan Consisted of Incinerating Japan With Bats Bearing Tiny Bombs
Dr. Lytle Adams, the brains behind the Bat Bomb. Pintrest

That idea in of itself was neither revolutionary nor original. It was common knowledge that the Japanese usually built their houses out of bamboo and paper, and in 1923, an earthquake had struck Tokyo, triggering fires that devastated the city, killing and wounding hundreds of thousands. So the vulnerability of Japanese cities to flames was well known. What set Adams apart was the creative method he dreamt up for igniting such fires: bats.

Adams had recently returned from a trip to New Mexico, where he was impressed by the clouds of migratory bats that visited the state each year, roosting by the million in Carlsbad Caverns. He was particularly impressed by the Mexican Free-Tailed Bats – a smaller but hardier species than common bats. So the dentist, who apparently had as much free time as he had initiative, returned to Carlsbad, and captured some bats to study.

This WWII Plan Consisted of Incinerating Japan With Bats Bearing Tiny Bombs
Size comparison of Mexican Free-tailed Bat, right, and a more common bat such as the Western Mastiff, left. Flickr

Between reading, observation, and experimentation, Dr. Adams realized that his nebulous idea of weaponizing bats might actually be doable. Bats – particularly Mexican Free-Tailed Bats – were hardy, could travel long distances, were capable of surviving in high altitudes, and best of all, could fly while carrying loads greater than their own body weight. Loads such as tiny, incendiary bombs. In theory, if bats with incendiary bombs were released over Japanese cities, they would naturally fly into and roost in the nooks and crannies of the mostly wooden buildings. Then the incendiaries would go off, starting numerous fires that would overwhelm firefighters, and cause widespread devastation.

Within weeks after the attack on Pearl Harbor, Adams had drawn up plans, and on January 12th, 1942, he wrote up a proposal and sent it to the White House. There, the idea would probably have been laughed off and dismissed out of hand, if not for the fact that Lytle Adams was a personal friend of Eleanor Roosevelt, the president’s wife. With help from the First Lady, the proposal made it to the desk of Franklin D. Roosevelt, and thence to the country’s top military brass. FDR thought it was “a perfectly wild idea but is worth looking into“. So he sent Adams to see William J. Donovan, Roosevelt’s chief intelligence advisor and eventual head of the Office of Strategic Services, the CIA’s predecessor, with a note advising him that “This man is not a nut!

This WWII Plan Consisted of Incinerating Japan With Bats Bearing Tiny Bombs
Canister bomb case, designed to hold hibernating bats. Wikimedia

The Concept

Adams’ proposal eventually ended up with the National Defense Research Committee (NDRC) – a 1940s’ version of DARPA, which investigated and coordinated research into ideas that might help the war effort. The NDRC forwarded the proposal to a zoologist named Donald Griffin, who had conducted groundbreaking research into animal behavior, and who specialized in bats and their navigation methods.

It was right up Griffin’s alley, and he became an enthusiastic supporter of the plan. “This proposal seems bizarre and visionary at first glance,” he wrote in April 1942, “but extensive experience with experimental biology convinces the writer that if executed competently it would have every chance of success“. He went on to add that, properly executed, Bat Bombs were “likely to cause severe damage to [Japanese] property and morale“.

Adams’ proposal thus went from a seemingly loony idea, to an official US government research project. A number of factors made the idea theoretically viable, and rendered it attractive to authorities. Bats fly at night, then seek dark and secluded places to roost in before dawn. Places such as attics, cubbyholes, and other nooks and crannies. Bats can also fly with loads exceeding their own bodyweight – loads such as tiny bombs. Also, during wartime, when resources were scarce and had to be carefully husbanded, bats were abundantly plentiful in the US. Finally, bats can be induced to hibernate, and while hibernating, they do not need food, care, or much maintenance.

This WWII Plan Consisted of Incinerating Japan With Bats Bearing Tiny Bombs
A bat house, brimming with recruits for Project X-Ray. Ripley’s Believe It Or Not

Dr. Adams gathered together a coterie of supportive scientists, then took a team of naturalists from the University of California on a bat collecting expedition. Their studies and observations confirmed Adams’ hunch that the Mexican Free-Tailed Bat was the best candidate for the project. So Adams’ team netted hundreds of Free-tails, placed them in refrigerated trucks to induce hibernation, and sent them to Washington for further research.

There, Adams conducted an experiment in front of military brass using some Free-tails and dummy bombs. The results impressed his audience, and convinced them that the plan, which was designated Project X-Ray, warranted serious research. The US Army Air Force was put in charge of the project, whose subject matter was described as a “Test of Methods of Scattering Incendiaries“. Testing and research was ordered, so as to “[d]etermine the feasibility of using bats to carry small incendiary bombs into enemy targets“.

This WWII Plan Consisted of Incinerating Japan With Bats Bearing Tiny Bombs
Bats, bombs, cannister, loading process, and an air drop during testing. Beach Back Packing

Effectiveness, and End of Project X-Ray

Work on Project X-Ray picked up the pace in 1942, starting with confirmation that bats could actually carry the weight of small incendiary bombs. Female bats routinely carry their young, and load bearing tests conducted at Moffet Field Naval Air Station in Sunnyvale, California, confirmed that the species can, indeed, carry its body weight or more in sustained flight. It was now time for the next step, so teams were sent to delve into caverns throughout the American southwest, to drum up bat recruits for large scale testing. The flying critters were captured by the thousands, and transported to research centers, where they were placed in specially constructed “bat houses”.

With the test subjects/ recruits in place, it was time to develop the tiny bombs that would transform bats into weapons of mass destruction. The job was given to Dr. Louis Fieser, an organic chemist best known as the inventor of militarily effective napalm. Fieser eventually settled upon a design for a light bomb made of a guncotton case, filled with kerosene. A capsule attached to the bomb contained a timed fuse and trigger assembly, which was affixed to the bat by a wire.

When the bat was released, the bomb would dangle from the critter by the wire, and its weight would activate the timed fuse, which would eventually trigger the incendiary. The Bat Bombs came in two models: a 0.6 ounce incendiary, which produced a 10 inch flamed that burned for 4 minutes, and a 1 ounce model, which produced a 12 inch flame that burned for about 6 minutes. By then the critters, released over Japanese cities, would hopefully have roosted inside attics and other nooks and crannies. In theory, the bats would gnaw through the wire connecting them to their incendiaries before they went off, and thus survive their mission and go on to live happy bat lives. If not, they would have the gratitude of Uncle Sam and the thanks of a grateful nation for their sacrifice.

To deliver the individual Bat Bombs to their target area, the critters were first induced into hibernation, then the tiny incendiaries were attached to them. Next, they were placed in a special bomb casing that contained 26 stacked trays, each with 40 bats, for a total of 1040 bat incendiaries per bomb. The bombs would be dropped at 5000 feet above a Japanese city, then deploy a parachute and break open at 1000 feet, releasing the by-now awakened bats to fly off and find roosting places.

This WWII Plan Consisted of Incinerating Japan With Bats Bearing Tiny Bombs
The Carlsbad Army Airfield Auxiliary Air Base, after it was accidentally set on fire by errant Bat Bombs during testing. Wikimedia

There were some testing mishaps, most notable of which occurred on March 15th, 1943, when armed bats, accidentally released at Carlsbad Army Air Field, New Mexico, set the place ablaze. The silver lining was that it confirmed that weaponized bats can, indeed, start major fires. More controlled weapons testing at a specially designed “Japanese Village” confirmed that Bat Bombs were, pound for pound, between 11 to 21 times more effective than standard bombs. As the project’s chief chemist noted: “the regular bombs would give probably 167 to 400 fires per bomb load where X-Ray would give 3,625 to 4,748 fires“.

Notwithstanding the promising test results, authorities pulled the plug on Project X-Ray in mid 1944, when they were informed that it would not produce a deployable weapon until 1945. That was deemed too slow a pace, and since the Manhattan Project was on track to produce a war-winning bomb by then, X-Ray was cancelled after a 2 year life and a $2 million expenditure. To his dying day, Dr. Lytle Adams insisted that his Bat Bombs could have won the war, with fewer horrors than atomic bombs. As he put it: “Think of thousands of fires breaking out simultaneously over a circle of forty miles in diameter for every bomb dropped. Japan could have been devastated, yet with small loss of life“.


Where Did We Find This Stuff? Some Sources and Further Reading

Atlantic, The, April 4th, 2011 – Old, Weird Tech: The Bat Bombs of World War II

Atlas Obscura – The Almost Perfect World War II Plot to Bomb Japan With Bats

Disciples of Flight – Napalm Bats: The Bat Bomb

Ripley’s Believe It Or Not – Bat Bombs Were in Competition With the Atom Bomb

Smithsonian Magazine, August 10th, 2015 – Bats and Balloon Bombs: The Weird Weapons That Could Have Won WWII

Wikipedia – Bat Bomb