What causes drain flies?
A gelatinous film inside the drain throat is the breeding ground. Larvae live protected inside the film. Foam treatment of the drain, not surface spray, is the only fix.
Why it happens
Drain flies thrive in the organic sludge that accumulates in pipes. This film of grease, soap scum, and other decomposing matter provides food and a protected environment for their larvae. The flies are a clear indicator of unsanitary drain conditions that can lead to odors and clogs. They are often found in floor drains, sink drains, and ejector pits that handle organic waste.
What to check
Regularly clean drain components, including overflows, with a brush to physically dislodge biofilm. Avoid caustic chemical openers, which can damage older pipes and may not remove the film where larvae hide. Surface sprays and bleach are also ineffective as they cannot penetrate the gelatinous layer. Consistent mechanical cleaning followed by a proper enzymatic foam cleanser is required to fully remove the source.
When to call a professional
If drain flies appear in multiple locations or persist despite cleaning, it suggests a systemic issue. A widespread infestation may originate in a sump basin, sewage ejector pit, or a main drain line with heavy sludge. These larger systems require specialized equipment and expertise for safe and effective treatment.
How Luften handles it
Luften addresses infestations at the source with a professional foam treatment that fills the pipe and clings to its walls, dissolving the biofilm where larvae develop. This service can be consolidated with maintenance for other building systems like grease traps and ejector pits. A single contract provides one point of contact for all drain, odor, and pest issues. A site survey can identify all contributing sources.
Drain odor elimination and drain fly program