Flexi Says: Decomposers are a type of organism that obtain food by breaking down the remains of dead organisms or other organic wastes into its various components, including nutrients, that can be used by other organisms. Most of the decomposers either are bacteria, fungi, or invertebrates (insects and worms). Decomposers are present in different types of ecosystems i.e. aquatic or terrestrial. For example, most marine decomposers are bacteria; earthworms are decomposers present in the soil.