Night soil is a historically used euphemism for human excreta collected from cesspools, privies, pail closets, pit latrines, privy middens, septic tanks, etc. This material was removed from the immediate area, usually at night, by workers employed in this trade. Sometimes it could be transported out of towns and sold on as a fertilizer. Another definition is "untreated excreta transported without water (e.g. via containers or buckets)". Night soil was produced as a result of a sanitation system in areas without sewer systems or septic tanks. In this system of waste management, human feces are collected without dilution in water. Night soil is largely an outdated term used in historical contexts, while fecal sludge management remains an ongoing challenge, particularly in developing countries. Collection and disposal Feces were excreted into a container such as a chamber pot, and sometimes collected in the container with urine and other waste ("slops", hence slopping out). The excrement in the pail was often covered with earth (soil), which may have contributed to the term "night soil". Often the deposition or excretion occurred within the residence, such as in a shophouse. This system may still be used in isolated rural areas or in urban slums in developing countries. The material was collected for temporary storage and disposed of depending on local custom. Disposal has varied through time. In urban areas, a night soil collector arrived regularly, at varying time periods depending on the supply and demand for night soil collection. Usually this occurred during the night, giving the night soil its name. In isolated rural areas such as in farms, the household usually disposed of the night soil themselves. Uses in agriculture Human excreta may be attractive as fertilizer because of the high demand for fertilizer and the relative availability of the material to create night soil. In areas where native soil is of poor quality, the local population may weigh the risk of using night soil. The use of unprocessed human feces as fertilizer is a risky practice as it may contain disease-causing pathogens. Nevertheless, in some developing nations it is still widespread. Common parasitic worm infections, such as ascariasis, in these countries are linked to night soil use in agriculture, because the helminth eggs are in feces and can thus be transmitted from one infected person to another person (fecal-oral transmission of disease). These risks are reduced by proper fecal sludge management, e.g.