then the oldest mouse said, " All mice must come to my hole tonight, and we will think what we can do about this cat." 

All the mice came. Many mice spoke, but none knew what to do. At last a young mouse stood up and said, "We must put a bell on the cat. Then, when the cat comes near, we shall hear the bell and run away and hide. So the cat will not catch any more mice."

then the old mouse asked, " Who will put the bell on the cat?" 

No mouse answered. 

He waited, but still no one answered. 

At last he said, "It is not hard to say things; but it is harder to do them."