This phrase is used to ask who will take on a difficult or risky task. It originates from an old fable where mice decide to put a bell on a cat to know when it is coming, but then they can't decide who will actually do it.
Examples
- Spanish: Tenemos que confrontar al jefe sobre los bajos salarios, pero ¿quién le pone el cascabel al gato?
- English: We need to confront the boss about the low wages, but who will bell the cat?