|Place of origin||US|
|In service||Never used|
|Wars||World War II|
|Weight||123 kg (271 lb)|
|Length||123 cm (48 in)|
|Effective firing range||32 kilometres (20 mi)|
|Maximum firing range||64 kilometres (40 mi)|
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. Dropped from a bomber at dawn, the casings would deploy a parachute in mid-flight and open to release the bats, which would then roost in eaves and attics in a 20–40 mile radius. The incendiaries would start fires in inaccessible places in the largely wood and paper constructions of the Japanese cities that were the weapon's intended target.
The bat bomb was conceived by a Pennsylvania dentist named Lytle S. Adams, a friend of First Lady Eleanor Roosevelt. Adams submitted it to the White House in January 1942, where it was subsequently approved by President Roosevelt on the advice of Donald Griffin.
Adams observed that Japanese structures were especially susceptible to incendiary devices as many of the buildings were made of paper, bamboo, and other highly flammable material. The plan was to release bat bombs over Japanese cities having widely dispersed industrial targets. The bats would spread far from the point of release due to the relatively high altitude of their release, and would then hide in buildings across the city at dawn. Shortly thereafter, built-in timers would ignite the bombs, causing widespread fires and chaos.
The United States decided to develop the bat bomb during World War II as four biological factors gave promise to this plan. First, bats occur in large numbers (for example, four caves in New Mexico are each occupied by several million bats). Second, bats can carry more than their own weight in flight (females carry their young—sometimes twins). Load-carrying tests were conducted in the dirigible hangar at Naval Air Station, Moffett Field, Sunnyvale, CA. Third, bats hibernate, and while dormant they do not require food or maintenance. Fourth, bats fly in darkness, then find secluded places (often in buildings) to hide during daylight.
By March 1943, a suitable species had been selected. The project was considered serious enough that Louis Fieser, the inventor of military napalm, designed 0.6 ounce (17 g) and one ounce (28 g) incendiary devices to be carried by the bats. A bat carrier similar to a bomb casing was designed that included 26 stacked trays, each containing compartments for 40 bats. The carriers would be dropped from 5,000 feet (1,525 m). Then the trays would separate but remain connected to a parachute that would deploy at 1,000 feet (305 m). It was envisioned that ten B-24 bombers flying from Alaska, each carrying a hundred shells packed with bomb-carrying bats, could release 1,040,000 bat bombs over the target of the industrial cities of Osaka Bay.
A series of tests to answer various operational questions were conducted. In one incident, the Carlsbad Army Airfield Auxiliary Air Base ( ) near Carlsbad, New Mexico, was set on fire on May 15, 1943, when armed bats were accidentally released. The bats incinerated the test range and roosted under a fuel tank.
Following this setback, the project was relegated to the Navy in August 1943, who renamed it Project X-Ray, and then passed it to the Marine Corps that December. The Marine Corps moved operations to the Marine Corps Air Station at El Centro, California. After several experiments and operational adjustments, the definitive test was carried out on the "Japanese Village", a mockup of a Japanese city built by the Chemical Warfare Service at their Dugway Proving Grounds test site in Utah.
Observers at this test produced optimistic accounts. The chief of incendiary testing at Dugway wrote:
A reasonable number of destructive fires can be started in spite of the extremely small size of the units. The main advantage of the units would seem to be their placement within the enemy structures without the knowledge of the householder or fire watchers, thus allowing the fire to establish itself before being discovered.
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. Adams maintained that the bat bombs would have been effective without the devastating effects of the atomic bomb. He is quoted as having said: "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."
The infamous "Invasion by Bats" project was afterwards referred to by Stanley P. Lovell, director of research and development for Office of Strategic Services (OSS), whom General Donovan ordered to review the idea, as "Die Fledermaus Farce". Lovell also mentioned that bats during testing were dropping to the ground like stones.
- Anti-tank dog
- Explosive rat
- Japanese Balloon Bombs
- Military animals
- Olga of Kiev (using "pigeons or sparrows" as offensive weapons in the 900s AD)
- Project Pigeon
- Madrigal, Alexis C. (14 April 2011). "Old, Weird Tech: The Bat Bombs of World War II". The Atlantic. Retrieved 31 January 2014.
- The Bat Bombers C. V. Glines, Air Force Magazine: Journal of the Airforce Association, October 1990, Vol. 73, No. 10. Retrieved 1 October 2006.
- Drumm, Patrick; Christopher Ovre (April 2011). "A batman to the rescue". Monitor on Psychology. 42 (4): 24. Retrieved 31 October 2013.
- Today's site : Carlsbad Caverns National Park
- Silverman, Steve (2001). Einstein's Refrigerator: And Other Stories from the Flip Side of History. Andrews McMeel Publishing. p. 122. ISBN 9780740714191.
- Lovell, Stanley P. Of Spies & Stratagems. Englewood Cliffs, N.J.: Prentice-Hall, 1963, p. 63.
- Waller, Douglas C. Wild Bill Donovan: The Spymaster Who Created the OSS and Modern American Espionage. New York: Free Press, 2011, p. 104.
- Bat Bomb: World War II's Other Secret Weapon, by Jack Couffer, University of Texas Press, 1992, ISBN 0-292-70790-8 (Bat Bomb project member Jack Couffer's document collection is housed at the Dolph Briscoe Center Archives at the University of Texas, Austin.)
- "Weird Weapons: The Allies". Modern Marvels. History Channel. 2006-02-08.
- Lovell, Stanley P (1964). Of spies & stratagems. Pocket Books. ASIN B0007ESKHE.
- Spy Gadgetry: Espionage Equipment Designed to Fight Hitler, by Alan Lance Andersen, GAMES Magazine, April 2000.
- Scott, Alan (1976). The Anthrax Mutation. Pyramid Books. ASIN B000R80FMI. ISBN 0515039497.