Read ‘The Bell and the Cat’, a fable by Aesop.

After a cat moved into their house, the mice all lived in fear. Something had to be done. So, one night, the mice held a meeting. They talked and talked, but no one could agree on a plan. Finally, the youngest mouse spoke up.
‘The problem is that the cat is so sneaky. We can’t hear her when she is near. Let’s find a small bell and tie it around her neck. Whenever she moves, the bell will ring. That way, we will always know where she is!’
The other mice clapped and cheered. It was a wonderful plan!
Then, the oldest mouse got up to speak. ‘All right’, he said. ‘But who will be the one to tie the bell on that cat?’
The mice just looked at one another. Nobody spoke up. They all thought it was a smart idea, but everyone was too scared to actually do it!