Where does the expression “to bell the cat” come from and What does it mean?

In figurative use the “to bell the cat” means to undertake a hazardous mission that may cost one his neck or his job, as when acting as ringleader in telling the boss that the working conditions are unpleasant.

It alludes to an ancient fable of mice and a cat. A family of mice, finding that fear of the cat so disturbs them that they are unable to forage for food, holds a meeting to discuss their problem and figure out some course of action.

After a prolonged session it is decided that the best solution is to get a brass bell and, in the words of Langland, in The Vision of Piers Plowman, “hangen it vp-on the cattes hals (neck); thanne here we mowen (we may hear) where he ritt (scratch) or rest.”

All agree upon the excellence of the scheme and they beam with pleasure over their cleverness. But the meeting is thrown into consternation when one graybeard steps forward, calls for attention, and solemnly asks the question, “Who will bell the cat?”

An historic use of the phrase occurred in Scotland in 1482. The king, James III, influenced by certain of his courtiers, imprisoned his two brothers. A loyal group of the nobles of Scotland determined, however, even at the risk of displeasing their sovereign, to save him from his courtiers by seizing them and turning them over to the assassin.

They found that it would be necessary actually to enter the king’s presence in order to apprehend the false counselors, but the Earl of Angus offered to run the grave risk and said, “I will bell the cat.”

The deed was accomplished, but, so history says, one of the king’s brothers had already died or had been murdered, and the other had fled to France.