Toward the end of World War II, the Air Force was looking for a more effective way to attack Japanese cities when Dr. Lytle S. Adams, a dental surgeon, contacted the White House with an idea. Adams suggested strapping small incendiary devices to bats, loading them into cages shaped like bombshells and dropping them from a plane. Bats would then escape from the shells and find their way into factories and other buildings where they would rest until their miniature bombs exploded.
The U.S. military began developing these “bat bombs” in the early 1940s, but the first test went awry when the bats set fire to an Air Force base in Carlsbad, N.M. After that, the project was turned over to the Navy, which completed a successful proof concept where the bats were released over a mock-up of a Japanese city. More tests were scheduled for the summer of 1944, but the program was canceled because of its slow progress. The U.S. military invested an estimated $2 million in the project.