Earthworm Castings: Nature’s Free Fertilizer

Those small, pellet-like mounds dotting the lawn aren’t guinea-pig droppings—they’re earthworm castings, a sign of healthy, biologically active soil. As worms tunnel, they ingest soil and organic matter, excreting nutrient-rich casts that improve structure, aeration, and fertility.

While the mounds can look unsightly on a manicured lawn, they’re beneficial. Simply flatten them with your foot or wash them away with a hose. No control is needed—or desirable.