Drain flies are fairly small measuring from 1.5mm to 5mm with light gray or tan bodies. They have a fuzzy appearance because of the long hairs that cover their body and wings and are sometimes referred to as “Moth Flies”.
You will find drain flies in kitchens, bathrooms and possibly basement walls because they feed on organic matter and sewage. They do not bite and are not known to transmit any diseases. They are just a nuisance.
Drain flies reproduce by laying eggs in decomposing materials. Drains are ideal because of the moist nutrient dense material that builds up inside the pipes. It is possible for a generation of flies to last two to three weeks. If you have clogged drains or sinks that are slow to drain, changes are you will see adult drain flies appear before too long.
Removing the clog will help but your Hart’s Exterminator will have a special enzyme that will breakdown the film in the walls of the drain where remaining larvae will be.