The Nazis had built fake airfields to fool their enemies. The British found out and dropped fake bombs on it!
There have been many interesting war tactics--certain battle techniques, surprise attacks, etc. The Nazis came up with a unique one that didn't turn out to be too successful. During WWII, the Nazis built fake airfields to deceive the Allies. Sometimes, these airfields had fake runways and buildings. They always had fake wooden planes though. These were called as "Attrappen."
However, the Allies discovered that these were fake airfields and displaying a peculiar sense of humor, dropped fake bombs on them. The bombs were actually made of wood too. And rumor has it that some even said funny phrases like "wood for wood." Seems like a lot of effort to make fun of your enemy.