Other little flies that like scummy places too!

Q. I’ve seen those little flies with the scaly wings before in my bathroom, but these flies are different. They scurry before they fly, and I’ve seen them on the countertops in my kitchen and bathroom. What are they?

A. The flies you are describing sound like humpback or phorid flies. Larva (maggots) of this group (Family:Phoridae) primarily feed on moist organic matter buildup found in areas that include drains, trash containers, disposals, sump basins, and broken sewer lines. A few phorids are parasitic on other insect species including an important new biological control weapon (Pseudacteon tricuspis) introduced to combat the imported fire ant.

By their presence, these flies (really all ‘pests’ do this) are telling you there is a problem somewhere. A condition in the home, or commercial building exists that the flies need in order to thrive that must be corrected in order to eliminate the problem. This involves a little detective work to find the source and the solution may be as simple as a thorough cleaning of trash receptacles, or cleaning out a sump basin with a wet-dry vac. Where things could get real expensive really fast is if the flies are coming from a back up or worse yet, a break in a sewer line that travels down through and beneath the foundation slab.