Drain flies often are a temporary problem. They develop in standing water so most commonly they are seen after returning home from a vacation or period of extended travel. Usually, they disappear soon after normal household activity resumes and water starts to move again through toilets and drain traps.
Once you've wiped out their breeding ground, the adults will eventually disappear because there is nowhere left for them to deposit their eggs.
Adult drain flies usually live about two weeks, but newly emerged adults rapidly replace them. These flies are also known as moth flies due to their appearance: they are small and furry with large, ovoid wings and prominent antennae.
If temperatures fall below freezing, and drain flies don't find a warm place to overwinter, they will die. But, drain worms (the larvae) can still survive by staying below the gelatinous film in drains. They will thrive all year round if the cold temperatures don't reach them.
Besides inadequate control measures, another reason why you have drain flies present again could be because there was a secondary infestation in another site that was not discovered or treated. There may be other bathroom drains, or a floor drain, laundry room drain, or sump pump that are breeding flies.
What Causes Drain Flies? Drain flies thrive in stagnant and standing water. Common sources include slow or clogged drains, rarely used and unused toilets, refrigerator drain pans, and standing water created by leaking pipes. They typically enter buildings through basements, windows, and drains.
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.
At night, when they are active, they will congregate towards light sources, like lampshades. They will also feed and breed at night, so you'll see them near food sources or breeding areas. You'll most likely see only a few at a time, as you only rarely see drain flies in large numbers at once.
Sources of Drain Flies
They can live most anywhere that water accumulates for a week or more. Common indoor sites include the fine slime layer that develops along the water surface in infrequently used toilet bowls and tanks, in sink or floor drains in basements or garages, or drain pans under refrigerators.
Behavior: Drain flies are most active at night. They are weak flyers that make short hopping flights of a few feet when they are disturbed. Drain flies rest on surfaces with their wings held over their back like a roof. You'll usually find a drain fly close to its breeding ground.
Bleach will absolutely kill drain flies. However, using bleach comes with certain risks. It's better to try other methods first and use bleach as a last resort.
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.
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.”
Lavender, eucalyptus, peppermint, lemongrass, and citronella are just a few of the scents that insects despise (with lavender probably being the most effective). Pouring half or an entire cup of such essential oil onto a sponge or rag, then storing it in a small can, helps keep flies at bay.
DIY Ways of Getting Rid of Drain Flies
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.
Drain flies are attracted to small amounts of stagnant water they find in plumbing pipes, sinks or other drainage areas. The flies feed on tiny amounts of bacteria, algae and sewage, so you can find them gathering around kitchen and outdoor sinks, shower and bathtub drains, basement sinks, sewers and septic tanks.
Answer: The drain flies are not coming up from the P-trap. They are traveling inside from outdoors and reproducing in the organic matter that builds up on the walls inside the drain. You should use 4oz of DF5000 drain fly gel in each drain in the infested room every night for a week.
They don't carry any pathogens that cause human disease. Heavy infestations may exaggerate asthma symptoms in some people, as the dried parts of dead flies float through the air, but that would have to be a very substantial infestation.
Drain flies are most commonly found in the bathroom, particularly in drains that have stagnant water or grime sitting in the pipes. Therefore, you'll probably find the small flies in the toilet, sink drain or shower.
Drain flies breed in the buildup in pipes. While it is less common for them to appear in a toilet, it could be they are entering the bathroom through a faulty seal between the toilet and sewer flange. This might indicate they are breeding lower down in the pipe and flying upwards.
These flies will breed in any moist area that they can find. So if you are facing a drain fly infestation that you cannot figure it out, you may want to look deeper for the cause. The problem could be from a leaking pipe or drain under the sink or even a leaking pipe inside of your walls.
Drain worms are essentially fly larvae. These species are also known as sewer flies, filter flies, or sink flies. They lay eggs, which hatch into larvae within 32 – 48 hours.
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.
Check under sinks in the kitchen and bathroom, especially around garbage. Consider investing in dehumidifiers for particularly humid areas of your home. Clean up and prevent any other sources of excess moisture, too. No matter how small it may seem, flies can and will use it.