During the Second World War, Allied forces attempted to sabotage German factories by stuffing dead rats with explosive charges. The idea was that a German worker would see the dead rat, and scoop it into the boiler fire for disposal.
This small explosive charge could then lead to a much larger boiler explosion, decimating the entire factory. The Nazis grew wise to the plan when they intercepted the first shipment. Although the plan was never fully executed, due to the resources wasted by Germans in checking all future dead rats it was considered a success.