Once the mice living in a certain house were very unhappy. The cause of their worry was that there was a cat who used to kill them regularly. At last they held a meeting to see how they could get rid of the cat. One mouse said they should leave the house. Another said that they should not come out of their holes. Then a young mouse stood up and said, "Let us tie a bell round the cat's neck. Then when the cat comes, we shall hear the bell and can get out of its way*. All the mice shouted "Good!" They all thought it was a very good plan indeed. Now an old mouse stood up and said, "The plan is, no doubt, good, but who will tie the bell round the cat's neck?” No mouse offered to do it. Suddenly the cat appeared, and all the mice ran into their holes.
Name the moral of the story​