An ecosystem is a place where living and non living things interact with each other to survive. The animals are part of the food chain because all animals need energy to live. Animals rely on plants or other animals for energy. All food chains end in decomposers. Decomposers are things that decompose other things, For example, worms decompose animals and molds decompose food or leaves and make mushrooms in the process. Decomposers are helpful to the environment because they remove unwanted stuff from the environment and return its energy to the earth . The sun is the main force of energy, so all food webs start with the sun. The sun is a ball of gas so it doesn’t rely on anything or anyone else to get it’s energy. If one animal becomes extinct, the whole ecosystem can go wrong. Then the secondary consumers may not be able to get their food.