Chicken Bomb

During the early years of the Cold War, Britain proposed placing nuclear mines along the eastern border of West Germany. These could be detonated when Warsaw Pact armies crossed, destroying them and deterring follow-on forces from invading Western Europe. But there was a problem with the mine design. It tended to freeze during the winter and become useless. So the British military considered nesting live chickens on the bombs. The body heat from the chickens would keep the vulnerable components of the bombs from become disabled:

Scientists working on the project realised that the bomb could fail in winter if vital components become too cold, so they explored ways of keeping the inner workings warm. One proposal put forward consisted of filling the casing of the nuke with live chickens, who would give off sufficient heat, prior to suffocating or starving to death, to keep the delicate explosive mechanism from freezing. Despite the potential importance of chickens to the project, the mine was codenamed 'Blue Peacock'.

The plan was never carried out.

Link via Dan Lewis | Photo by Flickr user MonkeyMyshkin used under Creative Commons license