The typical earthworm diet is decaying matter, humus, leaf litter, microbial fungi, and other microscopic organisms. Earthworms are important to the environment, breaking down organic matter and passing it through their gut as newly enriched soil. An earthworm has no teeth, so it swallows grit to help grind food in its multi-chambered gut. As an earthworm burrows and feeds, it aerates the soil and adds nutrients from deeper soil layers to upper layers, making easier new plant growth in the process. For this reason, they are valued by farmers and gardeners worldwide.