Once upon a time, there was a little bird named Timmy. Timmy had a fragile nest in a big tree. He loved his nest and was very happy there.
One day, Timmy found a big, round thing. It had a lot of weight. He thought it would be fun to play with it. So, he pushed it with his beak and it rolled down the hill.
The big, round thing rolled faster and faster. It went into the woods and disturb a family of ants. The ants were not happy, but Timmy did not know. He just kept playing with the big, round thing.
At last, the big, round thing stopped rolling. Timmy was tired and went back to his fragile nest. He learned that it was not good to disturb others. From that day on, he played with things that did not have a lot of weight and did not disturb anyone.
