Defense Media Network

Brilliant Mistakes: The Bat Bomb

To advance military capabilities, nothing works better than an innovative idea that hasn’t been tried before – sometimes. Ever since humankind walked out of caves and developed longbows, the stirrup, gunpowder and the airplane, brilliance and innovation, whether by accident or intent, have made militaries progressively more lethal. Sometimes, however, what seems a brilliant idea turns out to be a big blunder. “Brilliant Mistakes” is our ongoing series about ideas, weapons, tactics and strategies that didn’t work even after being perceived as the next giant step forward.

Enter the topic of bats and bombs.


Bats, Bombs, and an Oral Surgeon from Paint Lick

During World War II, an oral surgeon from Paint Lick, Ky., talked the U.S. government into using bats as bombers. The idea was to capture and employ thousands of bats to deliver incendiary bombs against Japanese cities. It seemed like a good idea because most Japanese urban areas consisted of houses made of wood and paper – and a firebomb attack would be devastating. If bats could be used to set Japan on fire, it could win the war without even risking American lives. Sinister, dark, silent and stealthy, the bat was the perfect weapon to alter the course of the war – it seemed.

The oral surgeon with the brilliant idea was Dr. Lytle S. Adams, who had visited the Carlsbad Caverns in New Mexico and had been fascinated by the small flying creatures he had seen there. After the Japanese attack on Pearl Harbor in December 1941, Adams realized that it might be possible to use bats as a delivery system for incendiary weapons. His vision:  thousands of bats like those he had seen in New Mexico would be fitted with tiny firebombs and then dropped from American planes over Japanese cities, towns and villages. The bats would then fly to Japanese houses, hide under their roofs, and the ordnance attached to them would set the wood and paper buildings ablaze. The resulting conflagration would set Japan on fire and win the war for America and her allies in the Pacific.

In January 1942, Adams wrote a letter to President Franklin D. Roosevelt, in which he proposed using bats as bombers. The White House passed the letter on to War Department, which liked the idea. The Army’s Chemical Warfare Service took the lead on the project and, in concert with personnel from the Army Air Forces, began to examine how best to transform Dr. Adams’ idea into reality.


Trying to Make a Bat Idea a Batty Reality

The first decision was the choice of bat. While hundreds of species exist, the most common North American variety is the small brown free-tailed bat, which ranges from 1 ½ to 4 ½ inches in length and weighs from one-third ounce to seven ounces. The creatures feed on insects and live in small groups or in large colonies.

An actual "bat bomb," which housed the bats with their attached incendiary devices

An actual “bat bomb,” which housed the bats with their attached incendiary devices. Trays were stacked vertically within the bomb-shaped container. When the tail-mounted propeller spun enough times to “arm” the bomb, the sides of the bomb disengaged and fell away, freeing the bats, and the remaining assembly descended beneath a parachute. Photo from Bat Bomb: World War II’s Other Secret Weapon, by Jack Couffer, University of Texas Press, 1992

Adams and a team of bat experts from California traveled by car to a variety of locations and ultimately decided that this common free-tailed bat was the best choice. They had two reasons. First, there were millions of them – more than 20 million alone in a cave that Adams and his colleagues found in Texas – and capturing them was relatively easy. Second, the free-tailed bat was strong enough to carry a one-ounce bomb, which the ordnance experts involved in the project thought could be designed and manufactured.

Dr. L. F. Fisser, a member of the National Defense Research Committee, designed two small kerosene incendiary bombs for Adams and his team of bat-bombers. The smaller bomb weighed about two-thirds of an ounce and produced a ten-inch flame that would burn four minutes. Fisser’s larger kerosene incendiary weighed slightly more than an ounce and produced a twelve-inch flame for six minutes. Each of the bomblets had a time-delay fuse, which used a copper chloride solution to corrode a wire holding back a firing pin. When the wire was sufficiently weakened, it broke. This released the firing pin, which ignited the kerosene.

The bombs were attached to the bats with a surgical clip and a piece of string. The idea was that the bats and bombs would be dropped from about 1,000 feet and, after the small furry creatures flew into hiding under the roofs of houses and other buildings, they would bite through the string, dislodge the surgical clip, and fly away – and leave the firebomb behind to work its magic. Of course, if a bat failed to separate itself from the bomb – well, sacrifices were required if the Japanese were to be defeated.


The Army’s Batastrophe

On May 21, 1943, the first major experiment with bombing bats got under way at Muroc Dry Lake, Calif., the site of the future Edwards Air Force Base. Some 3,500 bats had been captured in New Mexico and, to control them, the creatures were put into refrigerators

B-29 Superfortress dropping incendiaries over Osaka

Incendiaries were eventually used on Japan, but they were delivered in a more conventional fashion, by bombers such as this Boeing B-29 Superfortress of the 6th Bombardment Group, 24th Bombardment Squadron shown on a June 1,1945 mission to Osaka, Japan. U.S. Air Force photo

and forced into hibernation. When these bats were released with dummy bombs from a B-25 Mitchell medium bombers flying at 5,000 feet, however, most had not awakened from their refrigerator-induced sleep, did not fly, and crashed into the ground.

Subsequent bat drops from B-25s did no better. Getting the bats to awake from hibernation remained difficult, with the end result that more than a few failed to fly and died when they hit the ground. Many other bats simply escaped when they were dropped from altitude. The project was subsequently relocated to an Army auxiliary airfield near Carlsbad, possibly to be closer to a supply of bats to replace casualties.

When the Army finally began attaching real incendiaries to the bats, the experiment went awry when some bats escaped and set fire to an aircraft hangar and a car belonging to an Army general. About 6,000 bats were used in the Army experiments, which the Army Chemical Warfare Service ultimately concluded were a failure.


Bat Bomb Project Passed to Navy and Marine Corps

In August 1943, having had enough with bats and bombs, the Army passed Adams and his project on to the Navy and Marine Corps. The new bombing bats – now called Project X-Ray – were re-located to Texas. In December 1943, the Marine Corps managed to successfully launch free-tailed bats from altitude and the firebombs carried by these bats managed to start at least 30 fires. While most of the fires simply burned out, four them were of sufficient magnitude that professional firefighters would have been needed to extinguish them in an urban area.

The Marines planned to conduct more bat and bomb experiments in August 1944, with the plan to have the bats ready for operational action against Japan in mid-1945. When Chief of Naval Operations Adm. Ernest J. King was informed that Project X-Ray would take yet another year to come to fruition, however, King became annoyed and asked only a few questions before canceling the project. Altogether, the Army and the Navy had spent some $2 million on what seemed at first to have been a good idea but which turned out to have been very bad.

The idea of using firebombs against Japanese urban areas constructed largely of wood and paper did have merit, but the bombs were delivered in the form of M47 incendiary canisters dropped by B-29 Superfortress heavy bombers. The first full-scale firebomb attack, the March 9-10, 1945 mission to Tokyo, killed as many as 100,000 people (estimates vary) and leveled about 16 square miles of urban area, much of which contained home-based small factories for war materiel. The United States used firebombs – napalm – in the Korean War and they remain a lawful weapon of war, but none are in inventory today. Needless to say, no bats are in inventory today, either.


Robert F. Dorr is an author, U.S. Air Force veteran, and retired American diplomat who...

    li class="comment even thread-even depth-1" id="comment-10059">

    Doc Adams was brilliant indeed. Long before the Bat Bomb, he invented an energy-absorbing catapult device for in-flight Air Mail Pick-up. The Adams Air Pick-up was established in 1929 and All American Aviation was founded in 1937. The in-flight pick-up of mail service began on May 12, 1939 and carried airmail for ten years, a period during which mail volume boomed due to World War II correspondence. As the highway system was developed following the war, The company focused on passenger services and changed the name in 1952 to All American Airways. All American was the predecessor to US Airways. The engineering leg of All American split in 1953 and is now known as Engineering Arresting Systems Corp, a company that still manufactures energy-absorbing devices for aircraft arresting systems for both military and commercial aviation.

    li class="comment byuser comment-author-chuck-oldham odd alt thread-odd thread-alt depth-1" id="comment-10062">

    Thanks for commenting. That’s a really interesting aspect to the whole story that I personally never knew, although the author did.

    There are many great things about online writing, but one of the frustrating aspects is that the pieces have to be shorter to retain reader attention, so interesting information gets left out.

    li class="comment even thread-even depth-1" id="comment-10074">

    Often engaging a crazy idea leads to better, more workable ideas. I remember a young President back in the 60’s who had a crazy idea Americans would walk on the moon. The rest is history. You never know what’s gonna stick until you try it.

    li class="comment odd alt thread-odd thread-alt depth-1" id="comment-10394">
    pierre messerli

    Just one failure for many successes.

    li class="comment even thread-even depth-1" id="comment-10576">
    Marvin L. Tooman

    You don’t know what will work until you try!

    li class="comment odd alt thread-odd thread-alt depth-1" id="comment-46293">
    Willis B. Adams

    Dr. Lytle Schooler Adams was my father. You write up has a few mistakes; but then again it is basicly a repeat of dozens of other articles. There was so much more to the man and many other inventions. And so much more to the Bat Bomb. Like what did Bing Crosby have to do with it? Maybe I’ll Tell you Later.

    li class="comment byuser comment-author-chuck-oldham even thread-even depth-1" id="comment-46571">


    I’d appreciate hearing of any mistakes that might have been made in our article. I fact-checked the article and didn’t detect any, but it’s certainly possible that elements of the story were gotten wrong 70 years ago and were repeated in various reference materials, which are then consulted in good faith by writers and editors. It has happened before. I’m aware of at least a couple of your father’s other inventions, but the article wasn’t a profile, and couldn’t be, with the number of words to which it was restricted. We’d all be interested in what Bing Crosby had to do with it, should you wish to tell us later…

    li class="comment odd alt thread-odd thread-alt depth-1" id="comment-46574">
    Robert F. Dorr

    I’m one of the co-authors of the article, The article was written, edited and published by people who admire those who made a contribution to history and we work very hard, as required by publishing ethics, to be factually accurate. Separately from Chuck, I’ve reviewed the article and didn’t detect the factual errors to which Willis alludes I’ve requested Willis to provide the errors and his sources. More than 24 hours after my request, he hasn’t responded. We take factual errors seriously and Willis could be very helpful by responding to my request. So far as I know as of today, the article is factually accurate,

    li class="comment even thread-even depth-1" id="comment-47075">
    Willis B. Adams

    Some Answers from Willis B. Adams:
    It is not my job to do your research for you.
    First my father was an Oral Surgeon not just a dentist from Irwin. He was born in Paint Lick, Ky. and lived in many parts of the country. Irwin was were his second wife Mary Louise Drake’s family was from and they moved there in 1936. Her grandfather was Col. Edwin Drake who drilled the first oil well in Titusville, Pa. Most of the time they lived there he didn’t have a dental office. He was to busy with other inventions and activities. He ran for U.S. Congress twice. he was working on “The Air Mail Pick-up System” “Pellet Seeding” “A spherical Bomb Dispencer”
    His Air mail Pick-up was used to pick up guliders on D-Day and puick up prisoner of war behind the with the French underground. The first human pick-up was in 1944.
    The part of your article where it won’t be ready for another was pure spectulation in a report given by an officer who was no longer working on the project When the order came down from the Pentagon the project was being loaded aboard ship in Long beach harbor.
    Enough for now. I don’t need to do all your research for you.
    Willis B. Adams
    Your speculation that the bats had to be trained is wrong. The bats did what my dad wanted because that was there nature and that is why they were chosen.

    li class="comment byuser comment-author-chuck-oldham odd alt thread-odd thread-alt depth-1" id="comment-47139">


    Thanks for your comments. Train is possibly the wrong word. Employ might be a better one. I wish we had you as a source when writing the original article, because virtually every source out there states your father was a dentist rather than an oral surgeon. I’ll be happy to make that correction. As for where your father was from, even the DoD in original documents references Pennsylvania, since that was where your father lived at the time of the invention of the bat bomb. On the other hand, it will be a pleasure to change the sentence to read “…an oral surgeon from Paint Lick, Ky…”

    I’m not sure what you were trying to say in the last paragraph of your comments about an officer no longer working on the project, but feel free to follow up on that. Good luck with your book about your father, and thanks for your comments.