A natural source of soil wealth including indigenous microorganisms for ‘Restoring the Biology of Soils.’ Soil Secrets Worms are fed a diverse mix of Humus, compost, protein and other favorite foods.  Castings are a product of the digestion of organic matter by earthworms. Also contains earthworm eggs.   Earthworm castings provide mucilage that binds soils against erosion and holds water.