Decomposers are organisms that break down waste (such as fecal matter) and dead animals and plants in an ecosystem. Fungi, bacteria and scavengers are examples of different decomposers.
Scavengers are a type of decomposer that eat dead animals and plants, breaking them into small pieces as they feast. Some examples of scavengers are flies, wasps, cockroaches, vultures and earthworms.
The small pieces left behind by the scavengers are broken down even more by fungi and bacteria. Their feeding process allows the nutrients from the dead organisms and waste to return to the ecosystem's soil.
Decomposers are a valuable part of their ecosystem. They ensure that the soil gets refortified with nutrients, and they keep dead animals and plants and waste from piling up.