“During World War II, Project Pigeon (or Project Orcon, for "organic control”) was American behaviorist B. F. Skinner’s attempt to develop a pigeon-guided missile.

It was never used in combat. Although it seemed plausible, it was dubbed as ludicrous, and the project was scrapped. The 24 pigeons that Skinner had trained went home with him to live in his garden..“

further info here and here