Once there was a very beautiful garden. Near garden was a small stream flowing down. One day, a bee came there looking for flowers. Bee came flying over stream but while trying to pass through that, it's wings got wet and not being able to fly anymore, it got dropped into pool. Just near by a sparrow was sitting on a tree. Sparrow saw bee struggling and felt bad for it. So she plucked a leaf from tree and flew up to bee and souped bee with that leaf and dropped it out of water. As soon as wings got dry, bee was again able to fly. Bee thanked sparrow and flew back to it's comb. Some days later, sparrow was sleeping on tree. Bee was also flying around looking for flowers. Meanwhile, a boy was playing there and he had sling in his hand. Bee saw that boy was aiming his sling at sleeping sparrow. Bee understood boy's intention and as boy was about to shoot at sparrow, bee bit on boy's neck which made boy cried. The boy cried so loudly. The sparrow woke up and flew away. 
Do good for others and it will come back to you in unexpected ways. 