Soil is an important natural resource. Many things live in soil. Plant roots and insects are living things found in soil. Snakes, moles, and other burrowing animals make their homes in soil. Microbes are tiny living things that are too tiny to be seen without a microscope. Hundreds of thousands of them live in just a small sample of soil. But one of the most important animals that lives in soil is the earthworm.
Earthworms tunnel in the soil. Their tunnels give plant roots spaces to grow. The tunnels hold air and water in the soil.
Earthworms eat organic matter - bits of dead plants and animals - in the soil. As they eat, they swallow some soil, too. After the soil passes through the earthworm's body, it comes out enriched with nutrients - waste materials from the worm's body. This soil is loose and fluffy in texture. How much soil does one earthworm eat? One estimate is 36 tons in one year!