Bat bomb

Bat bomb
Bat bomb canister later used to hold the hibernating bats.
Type	Bomb
Place of origin	USA
Service history
In service	Never used
Used by	USA
Wars	World War II
Production history
Designer	Louis Fieser
Designed	January 1942
Specifications
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 construction 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. Dr. 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, then at dawn they would hide in buildings across the city. 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 (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.