Once upon a time, a thief stole a bell and tried to carry it away on his back. But the bell was too big and heavy. So, he decided to break it into pieces with a hammer to make it easier to carry. When he hit the bell, it made a loud noise. Afraid that someone might hear him breaking the bell, and try to steal it from him, he decided to plug his ears. If he couldn't hear anything, nobody else could either. A decision as foolish as this is sometimes compared with burying one's head in the sand.