This is a small gray-black flying moth, which will climb up along the sewer pipe, climb out when it encounters damage or lax floor drain, and fly up in the bathroom. As long as the water in the container is emptied and the water in the floor or sink is removed, the number of moths can be controlled. Insect growth regulators can be used for larvae bred in septic tanks. The flying ability of moths is very poor. Using electric mosquito swatter can effectively remove them. The chemical agent can be a synthetic pyrethroid spray (Mirex) for general household use. The most important thing is to keep the bathroom clean and pay attention to ventilation.