Question: In November we had a sewer problem. We have taken care of that, but since then we have a quite a problem with little flies that look like fruit flies.

I was told that they were sewer flies and we have tried everything to get rid of them. They will go away for a couple of weeks and then come back like twice as many is this something that you could help me with.

Answer: Phorid flies. Phorid flies are also known as sewer flies. This may be a good name for them, since they are often associated with damage to sewer lines that are in or close to the house or building. These flies are often associated with clogged drains inside buildings, especially in health-care facilities.

These are small brown to blackish brown flies that have a 'jerky' or erratic walking behavior. The adults will sometimes collect at windows, but often remain close to the breeding site. They do not bite or cause any problems on their own.

The immature stages of these flies live in the organic matter in clogged drains. Often they are found in hospitals and nursing homes and usually associated with drains that contain a large amount of organic matter, such as feces or even blood. They are often found breeding in large numbers in the soil around sewer lines that have broken, or in the soil around the drain pipes that have broken. The presence of phorid flies is an indication that high level organic material is present.

Control:Learn more about phorid fly control.

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

• Question: I believe my home has a problem with the Phorid - Humpbacked Fly. They are very small and I thought they were gnats. They are worst in the kitchen area which makes it hard to set down for a meal Can Orkin rid my home of these insects?

  Answer: It make take several days, and then it might take more than one treatment to kill all the larvae in carpeting.

• Question: PHORID FLIES! We have had several pest control companies take a look at our huge phorid fly issue. No one seems to know how to get rid of the bugs. I know we need to find the source but how can we do that?

  Answer: Check the sewer lines....pipes and all connections, inside and outside.

• Question: I think that I have phorid-humpbacked flies. They started in the kitchen, and are now expanding all over the apt. What can I do about this until my landlord gets an exterminator to come in and deal with it?

• Question: What is the best way to get rid of the humpback fly?

Read more about getting rid of sewer flies.