Drain Fly Facts

Drain fly, sewer fly, filter fly, moth fly — this is the fly of many names. Most names come from the places where this pest likes to lay eggs and develop into larvae. “Moth fly” comes from its fuzzy appearance. 

Drain Fly  Bites

Drain flies are not dangerous to humans or cause structural damage, but they become a nuisance in large quantities. Even though these pests eat sewage, they are not known to transmit any harmful bacteria. There have been some instances where asthma as been triggered by people who inhaled drain fly body parts. 

Drain Fly Infestation

Eggs are deposited during the spring and summer months in decomposing organic matter. These eggs will then hatch into drain fly larvae and will feed on this same organic material. In the right conditions, they will mature over the course of two weeks into pupae with a hard shell from which the adult fly is born.

One to three weeks is the average lifespan of the drain fly. They will feed on the nectar of flowers and polluted water. They will often be spotted indoors around windows, sinks, and walls. Moth flies will enter through areas where water is prevalent, such as sinks and drains.

Types of Drain Flies

Drain Fly Identification

Common names for drain flies are sewer fly, sink fly, filter fly and sewer gnats.

Adults are about 1/10 of an inch long (a third of the size of the common housefly). Its body is dark gray with light gray wings that are covered with long hair, giving it a fuzzy appearance. This is where the similarity with moths comes from.

Drain Flies In The House & The Bathroom 

These pests lay eggs and develop in the slime that builds up in pipes or drains. Adult flies are not very good fliers and you may notice them crawling on walls or other places in your home. Any stagnant water may lead to a drain fly infestation. Common spots for this problem includes drains, dirty trash cans, septic tank, leaking sewer system, the plates under potted plants and clogged gutters. These flies are also tiny enough to fit through most window and door screens.

Frequently Asked Questions

How do you control a drain fly infestation?

One of the easiest ways to control a moth fly population is to remove their breeding grounds. This means you will need to clean your sinks, drain pipes, and traps so that they are entirely clear of any debris. Getting rid of the slimy deposits with a wire brush will significantly reduce the presence of the drain fly. Once the breeding ground is gone, they will no longer reproduce.

What are the benefits of professional drain fly pest control?

Professional fly pest control services are necessary to effectively address a moth fly problem. Finding and treating the moth flies can be challenging, especially if they are hidden in the building. A fly removal and control professional provides their expertise to identify the pest problem, find out where the flies are coming from, and determine the best possible solution to resolve the drain fly infestation.