Organisms that digest molecules in organic material and convert them into inorganic forms are called decomposers. They are classified as heterotrophic since they use organic substances in obtaining the energy and nutrients they need to survive. They are organisms that are responsible for breaking down decaying organisms into simple molecules in order to bring these back to the biogeochemical cycles into the ecosystem. In the food chain, they are the last step. Examples of these decomposers are fungi, snails and some insects. These organisms do not have an internal digestive organs since the the organic substrates undergo biochemical reactions only.
