"Good" bacteria are an indispensable part of human existence. There is a "bacteria city" on the skin, with a total of 1 trillion bacteria. They always enjoy the buffet prepared by the human body for them: peeling dander, secreted oil and various minerals. While enjoying the feast, they strive to create a unique body odor for everyone. The Society of Bacteriology also conducts a "bacterial population census" like the Society of Anthropology. By releasing a chemical into the living environment, bacteria can count the number of members of their own population. After reaching a certain number, bacteria can begin to perform various tasks. Deep sea fish? ? ? ? This characteristic of bacteria is used to make luminescent bacteria gather on themselves. After the "roll call" is completed, the luminescent bacteria will automatically glow together to help? ? ? ? Attract prey in the dark sea.