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.

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

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.