What are these small, black, flying insects in my laundry room?

Question: I’ve noticed some flying insects have invaded my laundry room in the last few weeks. The only way to describe them is that they look like flies, but a bit smaller. They’re easy to kill, but they keep coming. When you kill them, they leave a mark on the wall as if they’re made of soot/dirt. What are they? How do you get them, and how do you get rid of them?

Answer: Probably what you have are drain flies or moth flies. The two most common species are Psychoda alternata and P. cinerea. Both these species can occur in households or commercial establishments throughout the year, but they may be slightly more abundant in the summer.

These small, gray flies have "fuzzy" wings and are sometimes confused with moths. The adult flies don’t move far from the site they infest, which is usually a drain. They are most often infesting the pipes leading away from floor drains, especially those drains that get a lot of organic material. In a home, this is usually the drain in the shower stall, tub, or in a washroom.

The immature stages of drain flies live in the accumulated organic matter in the drain. The larvae feed on this slimy material, and are usually "buried" in it. The fact that they are deep in the material makes them quite resistant to chemical control methods (regardless of how strong a drain and pipe cleaner you use.)

Call us, and a highly trained Orkin Pest Specialist will inspect your home, assess the extent of the infestation, make recommendations on things you can do to assist in the control of these pests, and develop a customized, scientifically proven treatment protocol that best fits your situation.

Related Questions

Orkin used the answer above to answer the related questions below (submitted by other Orkin.com users):

Question: What is the best treatment used for drain flies?

Question: Why would my home be attracting these "moths?" When you kill them, they turn to a dust like substance! I don’t know if they are really moths, but they only come around when our windows are open at night. We have screens in our home, so where would they come from and why? They also seem to be attracted to warm areas around lights and around water.

Question: I desperately need an answer. We have these small brown flying "bugs" that are getting worse. They seem to be around moisture. They are everywhere in my home. When you kill them, there is like a black smudge, like an ash-like substance. What are they?

Question: How do we get rid of gnats that come up through the drain pipes?

Question: It appears we are having a problem with drain flies at one of our restaurant locations. They seem to be breeding in the grease trap. Any suggestions as to how we can treat this problem?

Question: Can you get rid of drain gnats?

Question: My kitchen and bathroom are infested with drain flies and/or fruit flies. I got rid of the fruit and I have put Clorox down all the drains and sprayed bug spray yet I still have these pesky insects. Please help, what do I need to do to get rid of these insects?

Question: Recently I had a sewer clog. Since they opened the sewer I see these fast, flying black bugs in my home. There are two different types — one with big wings, the other with smaller wings — they seem to be attracted to light.

Answer: The ones with big wings are drain flies (= moth flies). The two most common species are Psychoda alternata and P. cinerea. Both these species can occur throughout the year. The small flies are called phorid flies.

Question: I have found some black worms in my bathroom. What are they, why are they there, and how did it happen?

Anser: What you have seen are probably larvae of the common drain fly or moth fly. The two most common species are Psychoda alternata and P. cinerea. Both can occur in households or commercial establishments throughout the year.

Question: We have small tiny black bugs inside the house that can be found in the kitchen, and bathroom. They fly around and land on walls and cabinet tops. What are they? How can I get rid of them?

Question: I have these little tiny insects in my bathroom around my sink tub. I think they are drain flies. If this is true, how do I get rid of them if they are behind the walls or in the drain overflow pipes or wherever they generate from?

Visit our Pest Library for information on how to control drain flies.