i need to how to write adventure story on food chain using these words engery, produces, decomposers herbivore, onmivore, consumer and i don't know how to do it.

Take one of the lowest herbivores on the food chain after she's just had a satisfying meal. Then write your story about how she and her predator escape from being eaten by other predators that day.

http://www.enchantedlearning.com/subjects/foodchain/