The non-green organisms like bacteria and fungi, which are incapable of producing their food, live on the dead decaying plants and animal bodies and are consumers of a special type. These organisms which break down the complex organic compounds present in dead organisms into simpler substances are called decomposers also known as scavengers. A perfect example of decomposers is, earth worms, wasp, cockroaches and flies. Some of the scavengers are microscopic which cannot be seen with our naked eyes such as bacteria. Bacteria are the smallest living organism, and the most numerous of decomposers. This organism can survive in any kind of situation. Fungi on the other hand, a simple including mould and yeast. Fungi as a decomposer is good breaking down thru the hardest substances like wood. The bacteria which act as decomposers are called putrefying bacteria. These organisms act as decomposers by the secretion of there body surfaces which decompose the organic matter present in the dead plants and animals and liberates ammonia carbon dioxide ace. They absorb some of these simpler substances for their own maintenance and release the remaining to the soil, water, and air to be used by the producers again. Producers are organisms which produce their own food, such as plants which produces their own food through photosynthesis.

The decomposers help in decomposing the dead bodies of plants and animals and hence act as cleansing agents of environment. The decomposers also help in putting back of the dead plants back, into the soil air and water for reuse by the producers like crop plants. This maintains the fertility of soil and the soil would continue to support the growth crops again. Thus, the decomposer organism helps in recycling the materials in the biosphere so that the process of life may go on like an unending change.

Thus decomposers protect the environment by giving back its important nutrient for fertilizing the soil for growing crops. In the Indian harvesting system, the farmers decompose the cows dung and use it as natural manure in the crops. The crops grown with this manure are healthy and more notorious than the crops which are sprayed by the chemicals pesticides and chemical manure.

The decomposers which stay in water are star fish and phytoplankton they help in the decomposing of dead animals and dead plants in water. They also help in absorbing the waste chemicals which are dump in the water and polluting the water.