Mother Wolf was magnificent animal. She had all the traits of a terrific hunter. She was very strong and fast. She knew how to hide and how to seize prey. Mother Wolf was the forest's supreme creature. Her skills were evident to all the other animals. Mother Wolf lived in a den beneath a tree with her cub, Little Wolf. At dawn, Little Wolf and Mother Wolf were eating breakfast. Little Wolf looked sad. Mother Wolf said, "What is wrong, my cub?" Little Wolf said, "I want to be big like you. You can run and leap better than anyone. You can howl so loudly. Being big is a necessity, and I am so small." Mother Wolf said, "Don't be dissatisfied with your size. Being small can be very helpful somtimes." Just then, rain and hail began to fall. The tree was hit by lightning. It fell on the wolves'den. Little Wolf was scared. The wolves knew that escaping the den was vital. Mother Wolf said, "Little Wolf, I cannot move the heavy pile of branches. But you can escape with ease. You can get out and find help!" Little Wolf crawled out of the den and called all the large animals for help. They went to the den and pulled away the branches. Mother Wolf came out and said, "Thank you Little Wolf! You saved my life!" She softly squeezed Little Wolf and kissed her. Little Wolf smiled. She said, "Mother, this outcome has taught me a profound lesson. Even though I'm small, I'm still important." 请用一句话概括这篇短文讲述了一个什么故事。