Drain flies can breed outdoors during the summer with adults entering homes through open doors or windows. Low, wet areas where air conditioning units drain, or clogged guttering are excellent places for these insects to develop.
In some instances, the breeding grounds can be outside your home. Potential locations include compost piles, animal waste, storm drains with standing water, birdbaths, barns, and wet areas around garbage.
Drain flies gather, mate, and lay eggs in moisture or standing water. The slimy film that forms in sewers and drains is a favorite breeding spot. Putting off regular cleaning and maintenance of these areas may attract the pests and offer them a place to feed and develop.
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.
Dish Soap and Warm Water
Kill drain flies in the sink basin, wall, or ceiling using a dish liquid and water mixture inside a spray bottle. Add two cups of warm water and 7 drops of dish liquid and shake. When you spot a drain fly, spray the fly with the mixture.
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.
The good news is most drain fly issues can be fixed within about a week with regular cleaning and careful attention. Here are five ways to do so: Start with cleaning your sink and drain with your usual cleaning solution. Use a pipe brush to scrub around and inside the drain.
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 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.”
A cup of household bleach is generally more than sufficient to kill most drain flies, and all you need to do is pour it down the affected drain.
Make a natural cleaning/fly killer mixture.
Mix together 1/2 cup of salt, 1/2 cup baking soda and 1 cup of vinegar. Pour the mixture down the drain. Let sit overnight, then flush the drain with hot water in the morning. This should kill all flies and the organic material they've been feeding on.
Life Cycle of the Drain Fly
Three weeks. That is all the time the drain fly has to live, and yet they make good use of that time in terms of reproduction. In a typical drain fly litter there are between 30 and 100 eggs, each of which are laid in shallow water and can hatch in as little as three days.
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.
Do Drain Flies Die in Winter. Most fly species cannot survive outside temperatures below 32°F (0°C). They die unless they find a warm and conducive place to overwinter, such as your home. Drain flies are one of the few insects that can tolerate cold weather conditions.
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.
Drain flies are typically only found in the summertime or in places with moderate year-round climates. Cold weather kills off more drain flies than any of their predators. If drain flies are able to find a home indoors, they can continue their development throughout the year, even during the winter.
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.
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.
Drain flies gather, mate, and lay eggs in moisture or standing water. The slimy film that forms in sewers and drains is a favorite breeding spot. Inside structures, they are strongly attracted to light and will be found on glass windows, doors, lamps, and indoor lighting.
Learn the Pest Biology
Life Cycle: Adult females lay 30–100 eggs in sludge around sewage and drainage areas. Eggs hatch in 32–48 hours, larval stage lasts 8–24 days, pupal stage 20–40 hours. Adults live about two weeks.
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.
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.