Crows and pitchers

Once upon a timeOnce a thirsty crow was flying here and there in search of water. But it didn't get water anywhere. At last he saw a pitcher nearby and it flew away to a distant pitcher. He wanted to get a drink from the pitcher. It was at the bottom of it.It saw little water at the bottom of it. Soon it entered its lip pitcher. It could not reach its lips in any way. But it did not discourage it. Suddenly it was some rock a short distance away He saw it. He made a plan. He took stones and threw them into the pitcher. When it dropped one stone at a time, the water in the jug rose high enough to reach inside. Then drink water at an interval Is satisfied.