We have drain/sewer flies. We’ve been dealing with a plumber, suggested we try an exterminator. We’ve been using the exterminator, but still have an issue. The exterminator said there’s nothing more they can do, to call the plumbers back. They came today, busted the wall from behind our dishwasher exposing a pipe and an area they appear to be coming from. We’ve noticed them coming in from this area, and a sewer smell often. They are digging up the slab in that area to try and make repair. There is a possibility they will have to dig the slab up further costing $3000-$4000. We are prepared to pay it, IF this will get rid of these flies? If we pay this is it going to work?

The exterminator has better knowledge about your particular situation and may should have more accurate information that we can supply.

Years ago I had hundreds of drain flies coming out of my bathtub trap. Called my local extension agent who said to pour a cup of clorox into the drain and then to cap it overnight. Never saw another drain fly.