The food chain is essential to the world’s ecosystem. Two of the important groups included in this chain are scavengers and decomposers.
Scavengers are animals that prefer to eat dead animals, or carrion, rather than catching live prey. Some examples of scavengers are foxes, vultures, hyenas, and crows. They have excellent eyesight and a heightened sense of smell, which they use to track down their prey. But not all scavengers eat other animals. Some, like earthworms, live off the energy they get from plants, called Cellulose. Cellulose is a rich source of energy contained inside the cell walls of plants.
Like scavengers, decomposers are a crucial part in the food chain. This group includes fungi, insects, bacteria, and mold. Decomposers like fungi and mold don’t make their own food; instead, they grow on dead plants and animals. Specifically, decomposers grow in large groups on rotting food and garbage, from which they soak up their nutrients.
So what makes scavengers and decomposers are an important part of the food chain? They simply put, recycle carbon, nitrogen, and oxygen into the air and soil due to the ways they get nutrition. Even though living things like crows and fungus might seem small and unimportant, it's actually beings like these that make life for all other forms possible!
[Source: Life As We Know It]