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.
The good news is most drain fly issues can be fixed within about a week with regular cleaning and careful attention.
They won't go more than a few feet, and it might seem as though they're hopping rather than flying. They also don't bite. Nine times out of ten, a drain fly problem will go away on its own.
Drain flies may keep coming back due to poorly executed or ignored mechanical cleaning; failure to eliminate all breeding grounds, surviving eggs, and larvae; and failure to conduct regular cleaning and maintenance of the drain pipes. Adult flies can continue to get in from outside, so seal all possible entry points.
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.”
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.
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.
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).
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.
Most exterminators use chemical methods and habitat modification to kill all eggs, larvae, and adult drain flies (removing food sources, etc.).
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.
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.
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.
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.
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.
Your kitchen sink and garbage disposal is paradise for drain flies. Their ideal breeding environment is wet, humid, and laced with food waste to feed on. Your first course of action to deal with drain flies is prevention. Don't throw anything down your garbage disposal that will cause build-up.
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.
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.
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.
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.
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.
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.
IT STARTS WITH MAGGOTS IN YOUR DRAINS!
It's the larvae or maggots of these flies that live inside the drains, feeding on the gelatinous goo that forms on the inside of the pipes.
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.