Vermicomposting is the process of using earthworms to break down organic waste in order to create a faster than normal composting. The worm population is self regulating and will increase to the point where available food and space constrain further expansion. The process must be monitored for such parameters as moisture content and temperature but is not labor-intensive. Compared to ordinary soils, the earthworm castings (the material produced from the digestive tracts of worms) contain much more nitrogen (N), phosphorus (P) and potassium (K). They are rich in humic acids and improve the structure of the soill if used as a soil conditioner. The worms are placed in bedding made of loose materials such as coconut husk or shredded paper in a shallow box or tub and fed with soft organic matter such as kitchen waste. After about two months the compost can be harvested by putting the compost in the shape of a cone and scrapping of the top layers. The worms go to the bottom of the cone as they run away from light. Vermicomposting is a popular sustainable low-cost treatment for organic solid wastes (kitchen wastes, plant wastes). It is also applied to treat fecal matter, such as human excreta in the form of sewage sludge, sieved blackwater or faeces. Vermicomposting is also used to produce Terra Preta.