American missionary was visiting a village in Borneo. The village had a tiny local bird, called the "Foo," that hung around the village and was a scavenger.

The missionary noticed that all of the tribe's people had piles of something on their heads and shoulders. He asked what it was and was told that the Foos flying overhead would defecate, as birds do, and sometimes it hit people. The tribe had an old belief that it was good luck and that removing it was bad luck. People that had the highest piles were looked upon as favored by the gods. They took great pains not to disturb the accumulated Foo droppings. They added that removing them would result in death.

The missionary said that was nonsense and when the first Foo dropped on his head, he took out his handkerchief and cleaned it off. He immediately dropped dead.

The tribe started chanting, "If the Foo sh#ts, wear it!"