Drain Fly Control in Portland
Drain flies are small, fuzzy and persistent, and they breed in the gunk lining your pipes. Cleaning the source ends the cycle.
Drain flies, also called moth flies, look like tiny gray moths resting on bathroom walls and around sinks. They are not dangerous, but they multiply fast and a handful in the evening can mean hundreds breeding below.
Their larvae live in the slimy film of organic matter that builds up inside drains, overflow openings, floor drains and condensate lines. Without that film, there is nothing for the larvae to eat.
Finding the breeding site
A flashlight and a bit of patience are enough to find most sources. Tape a clear cup over a suspect drain overnight and see whether flies collect inside. Seldom-used guest bathrooms, basement floor drains, utility sinks and shower drains are common.
Why sprays fail
Killing adults gives short-term relief, but the next generation emerges from the drain in days. Pouring bleach rarely reaches the biofilm either. Effective treatment physically removes the buildup and then uses a biological or residual product so it does not return quickly.
When the issue is bigger than a drain
If flies persist after the drains are cleaned, the cause may be a cracked line, a leak under a slab or a sewage backup. We tell you plainly when a plumber is the right next call.
What to watch for
Floor drains
Rarely used, often dry and full of organic film, they are the most common source.
Sink and shower overflow
The overflow channel is out of sight and almost never cleaned.
Condensate lines
Water heaters, HVAC and dehumidifier lines can host larvae.
What happens on a visit
- Inspect and test the drains you suspect
- Clean the drain and apply treatment to the buildup
- Treat adult flies in the room
- Explain how to keep drains from refilling with film
Read next: Fruit Flies, Cockroaches, Other Insects.
Drain Flies questions
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