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. Leave overnight, and finish by pouring boiling water down the drain in the morning.
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.
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.
Most exterminators use chemical methods and habitat modification to kill all eggs, larvae, and adult drain flies (removing food sources, etc.).
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.
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.
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.
Adult flies emerge from the breeding sites but may remain nearby. Drain fly control often fails because people don't realize just how resistant the scum and the larvae are to boiling water, bleach, detergent, and even caustic drain cleaners (see How Can I Get Rid of Drain Flies?).
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.
The larval stage of drain flies lasts up to 24 days, while the pupal stage lasts between 1 and 2 days at most. The larvae feed on bacteria, fungi, and other microorganisms that develop in the breeding medium in drains, standing water, and even sewage treatment beds.
Once you've wiped out their breeding ground, the adults will eventually disappear because there is nowhere left for them to deposit their eggs.
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.
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.
While this chemical might get rid of some larvae, bleach passes quickly down the drain and does not penetrate the thick build-up where eggs are deposited by the female drain fly and larvae live. As a result, in most cases, bleach does not get rid of drain flies.
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.
Create a fly and wasp repellent.
This DIY pest repellant should be a staple in the Southern home. Pour equal parts water and Pine-Sol in a spray bottle to spritz on outdoor furniture, the deck, and indoor areas where flies are most likely to flock to, such as kitchen countertops.
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.
During the day, you'll notice drain flies resting on the wall since they aren't good fliers. 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.
They reproduce in polluted, shallow water or highly moist organic solids where they feed on decaying organic material in mud, moss or water. In homes, the adult flies are most likely found on the walls of the bathrooms, kitchens, basements and other locations where sewer drains and plumbing fixtures are located.
To make an all-natural drain fly trap, fill a bowl with apple cider vinegar and cover it with plastic wrap. Punch small holes in the wrapping. The vinegar's smell will attract the drain flies, and the wrap will trap them inside the bowl. Another option is to mix a few drops of dish soap with a cup of vinegar.
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.
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.
Drain flies do not come up from your pipes or drains, rather they come from outdoors to the drain when they smell the organic matter they need to breed. Drain Flies get into your home through tiny holes. Drain flies are most active in the evening when they congregate around sinks and drains.