Their tunneling behavior enhances the soil’s structure, reducing runoff into our rivers and streams, and thus helps prevent soil erosion.Moreover, the nutrient-dense humus produced by earthworms can improve the quality of water by serving as a natural filter, absorbing harmful toxins and pollutants.An Insight into Earthworm DiversityDespite their seemingly simple exterior, earthworms are a diverse group with a variety of species each playing a unique role in the ecosystem.