In fact, in ancient times, there was a special business to buy feces. "I would rather be dirty than clean." The most famous dung digger is Shi Chuanxiang, a national model worker, who was warmly received by the central leadership. The treatment of feces involves the sanitation of the city and the most basic civilized quality of residents' life. Nowadays, dry toilets have long disappeared, and high-tech public toilets, star-rated public toilets with special facilities for the disabled, mobile public toilets and other "fashionable" toilets have appeared one after another. Manure cleaning is pumped by cars, and dung diggers have disappeared in modern cities.

The treatment of feces is also being modernized, turning waste into treasure. The feces collected in septic tanks will form layers of sewage and sediment after being deposited in septic tanks for a period of time, and then these feces will be decomposed by some microbial molecules, most of the residues can be decomposed, and the volume of the residues that cannot be decomposed will be greatly reduced, which is also very convenient for later treatment.

Most of the solids are taken away by the sanitation department after dissolution, fermentation and sterilization. These crops can be used as agricultural fertilizers, which trees and crops need to fertilize the land. More feces are processed and refined by factories. The treated residue can be used to irrigate farmland, plant flowers and grass, etc. Even if it is discharged into rivers, lakes and seas, some of it will drift with the tide and eventually reach the sea. Some of it will be eaten by fish and shrimp plankton along the way, and some of it will be decomposed by microorganisms and eventually consumed by nature and become a part of nature. People from there go back there. As the saying goes, falling red is not a heartless thing, but turning into spring mud protects flowers more.