Have you ever heard of sewer gnats? If you haven’t, maybe you have seen them? They look a lot like a fruit fly, but their wings aren’t as clear. Sewer gnats live in the sewer, so you will usually find them buzzing around in your bathroom or laundry room. When you swat at them, they leave behind a trail of black dust. The problem with sewer gnats is that they nest inside of your sewer, so it is very difficult to completely eradicate them. A sewer gnat nest can survive boiling hot water being flushed down the drain, as well as, many different types of chemicals. Your best method for getting rid of them is using a snake to get the nest and flush out the larvae.
It is important to keep doing this a little while after you have stopped seeing live sewer gnats in your home, since there could be another generation growing somewhere getting ready to leave the nest.