Why are small-bristled worms useful?

Small bristle worms live mainly in the ground and in water bodies. They do a lot of good. 1. Feeding on decaying organic substances, they recycle them. As a result, the earth receives a substance nutritious for plants – humus. 2. Worms living in water bodies also cleanse them. 3. Due to calcium carbonate, which worms release into the ground, its acidity can decrease. 4. Constantly moving in the thickness of the earth, the worms stir it. This makes it easier for air and water to enter the soil. 5. Such representatives of small bristles as earthworms are valuable food for many birds and fish.