Drain flies, or moth flies, are small, darkwinged, non-biting gnats. Their wings are covered with scales so they disappear in a cloud of fine dust when swatted or mashed. These nuisance gnats can be found resting on walls or ceilings, and make short hopping flights if disturbed.
These pests live and breed inside your plumbing pipes, feeding on decomposing material and laying eggs within the gelatinous slime that collects along the interior walls of your drain. Adults can be spotted resting on walls and ceilings of the infested areas.
If you notice a big amount of drain flies in your home then you likely have issues with poor sewage drainage or overflows, which make a happy breeding ground for these pests. Make sure to contact a pest control professional to handle a potential infestation.
One common remedy for killing drain flies is using household bleach. This is a very useful and cost-effective manner for getting rid of these little pests with an item you already have around the house.
You can start by spraying your sink and down into your drain with a 1-to-3 mixture of water to standard 5% vinegar. Or, you can simply pour a pot or kettle worth of boiling water down the affected drain (just be very careful when you do it). Either way, follow up with a deep clean of your drain and sink.
Regularly cleaning your drains will kill the larvae and the adult flies. You can opt for a commercial cleaning product—such as a bleach solution or a chemical cleaner—or a do-it-yourself (DIY), environmentally friendly solution.
Identifying the Source
For the plastic cup method, lightly coat the inside of the cup with vegetable oil or petroleum jelly then invert the cup over a drain where you suspect flies may live. Leave the cup in place for several days, but check it daily.
A super simple fix is to pour boiling water down the drain to eliminate drain flies. Boil a medium-size pot of water once or twice per week, and pour down and around the drain. Another easy option uses baking soda: Combine 1/2 cup salt with 1/2 cup baking soda and 1 cup of vinegar, and pour down the drain.
Essential oils are sometimes used to keep flies away from infested sections and also to kill them. Lavender, eucalyptus, peppermint, lemongrass, and citronella are just a few of the scents that insects despise (with lavender probably being the most effective).
For effective drain fly treatment, use three products: Forid Drain Gel Cleaner, Gentrol IGR Aerosol, and Pyrid. Forid is an organic microbial grease degrader that breaks down organic material and waste, which will eliminate their food sources and their breeding grounds.
During the day, adults rest in shaded areas or on walls near plumbing fixtures and on the sides of showers and tubs. Most activity occurs during the evening when these flies are seen hovering about drains and sinks.
One possible sign of an undetected mold problem in your home or office could be the presence of Phorid flies, sewer flies or some other gnats or bugs.
A: Flies do have a larval stage. You have blowflies in the house and the larvae are in the wall or ceiling feeding on a dead animal of some sort. When they pupate and emerge as adult flies, they are attracted to light and will find their way out of the wall/ceiling and into the house, where you notice them.
They will breed in any moist area that they can find. So if you are facing a drain fly infestation that you can not get a handle on, you may want to look deeper for the cause of these insects. It could be stemming from a leaking pipe or drain under the sink or even a leaking pipe inside of your walls.
For the most part, drain flies are not dangerous and not harmful. Having drain flies around your home does not mean your drains are dirty or your kitchen, bathroom or other areas are unclean. They are opportunistic insects and can get inside and find any moist area to lay their eggs and breed.
Baking Soda, Boiling Water & Vinegar
The pour half a cup of bicarb soda down the sink as well, followed by a half cup of white vinegar. Let it settle for a few minutes then poor some more boiling water down the drain. Follows these steps every few days until the drain flies have completely disappeared.
They are attracted to rotting food, feces, human hair, and moisture. You can also find them in humid, warm, and poorly ventilated areas. Drain flies are attracted to dirty drains, standing water, and slow-moving or clogged drains.
They do not bite, sting, or spread diseases, but their decaying bodies may cause allergic reactions. They can also spread bacteria from trash, decaying vegetables and fruits. Drain flies breed in areas that are moist and have a lot of organic remains, including: Sinks.
"Combine 1/2 cup salt with 1/2 cup baking soda and 1 cup of vinegar and pour down the drain." Leave it overnight, and in the morning, pour boiling water down the drain. "This is a natural remedy that will clean the plumbing pipes and remove the breeding grounds for these flies," he explains.
Adult drain flies usually live up to two weeks as long as a liquid food source, such as nectar, is available. A large amount of flies in the home typically indicates a problem with poor sewage drainage or overflows, which can become a continuous breeding ground.
One of the reasons that these types of critters — drain flies, in particular — are so difficult to get rid of is that they have water-repellant hair all over their bodies. Furthermore, the drain fly larvae are difficult to drown since “they are able to trap air bubbles and remain submerged for a day or more.”
Preventative Maintenance
Pouring bleach into the drain when the unit is not operating can leave residual bleach, which will damage the drain pan and line. Using vinegar for preventative maintenance throughout the year will keep your drain clean and clear and will not damage your line.
What are the signs of a drain fly infestation? As with most flies, the most noticeable sign of drain flies are the adults. They typically are seen resting on the walls in bathrooms or near the breeding materials. Larvae also may be observed wriggling in the breeding material.