I was playing a barbarian once who noticed that the gargoyle statues arranged around the room were real gargoyles who were just waiting to get the drop on the party. He went up to one and murmured in its ear that if it was really clever it would just keep on pretending to be a statue.
When the inevitable ambush was sprung not only did that one stay where it was, the one next to it that had made its perception check well enough to overhear also stayed still. They survived.