Mouse Tower
http://en.wikipedia.org/wiki/Mouse_Tower
“When Hatto retired to his castle, he was instantly besieged by an army of mice. He fled the swarm and took a boat across the river to his tower, hoping that the mice could not swim. The mice followed him and rushed into the river by the thousands. Many of them drowned, but even more crawled onto the island. There, they ate through the tower’s doors and crawled up to the top floor, where they found Hatto and ate him alive.”
