just watching The Worlds Weirdest Weapons - the CIA tried to use a cat to get a listening device into somewhere sensitive - bloke just said "in the real world getting a cat to go where u want it isn't easy" - no shit!?!
On one of the trials the wind changed so the bats burned the military base to the ground instead of the target fake village. There was a WW2 guided bomb that utilised a pidgeon trained to peck pictures of battleships. He got a window and where he pecked it altered the fins.
I remember watching Hitler's underground cannon where there are explosive charges which are timed to accelerate a projectile up the barrel. Apparently it never worked as planned.