The bat bomb was conceived by a dentist named Lytle S. Adams, a friend of First Lady Eleanor Roosevelt. It consisted of a casing (see picture) with 1000+ compartments, each containing a hibernating Mexican Free-tailed Bat with a small timed incendiary bomb attached. Each bomb 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 wood and paper construction of Japanese cities.

Four factors gave promise to this plan.

1 Bats occur in large numbers.

2 Bats can carry more than their own weight in flight.

3 Bats hibernate, and while dormant they do not require maintenance.

4 Bats fly in darkness, then find secluded places in buildings to hide during daylight.

The bomb was designed to include 26 stacked trays, each containing compartments for 40 bats. Dropped from 5000 feet, the trays would separate but remain connected to a parachute deployed at 1000 feet. 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 industrial cities of Osaka Bay.

But the bats wreaked revenge during tests at the Carlsbad Army Airfield Auxiliary Air Base, NM. In May 1943 armed bats were accidentally released: they roosted under a fuel tank and incinerated the test range. So the project was then transferred to the US Navy. They passed it on to the Marine Corps...

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