For our convenience, we will divide the process of getting rid of drain flies into two parts. The first part will deal with the cleaning of drains to destroy the drain fly eggs and larvae, while the second part will deal with the killing of adult flies.
So, here we go:
Part 1: Destroying the breeding source:
Now once you have identified the breeding source, you can begin the process of eliminating the slime and dirt deposited in your drains where these flies breed.
1. First clean the drain, from outside. And then pour 2-4 litres of warm water to moisten the drain.
2. After this, use a metal pipe brush and push it through the pipe, move it in a up and down motion to clean the sides of the pipe. You could also use a plumbing snake to pull out the grime.
3. Next, pour a drain cleaner gel into the pipe trying to coat the sides of the pipe. Drain cleaner gel is specifically formulated to remove the organic matter from the pipes.
Many people say that instead of drain cleaning gel you could also use boiling water and bleach, but these methods are not effective against drain flies because drain fly larvae can survive under high temperatures.
4. After few hours of application of the drain cleaner gel, pour plenty of water. You could also use a plunger to flush any remaining organic matter trapped in the pipe.
Part 2: Killing the adult Drain Flies:
After removing the drain fly eggs and larvae by cleaning the drain, you are only left with the adult flies. Since they now have no place to lay eggs, your drain fly problem will disappear when these adults die. To kill these adult drain flies you could use sprays, or swatters. Below is a list of some methods that you can use to kill the adult drain flies:
1. Using Chemical Sprays: You could use chemical sprays to kill the mature drain flies. But the problem with chemical sprays is that they are toxic and hence cannot be used if the infested area is kitchen.
2. Using Fly Swatters: As drain flies are mostly seen resting on the walls so it is much easier to kill them using a mechanical fly swatter. But after killing them make sure to clean the bloody mess from the walls using a damp cloth.
3. Using Liquid Dish Soap Spray: Dish Soap contains borax, which has insecticidal properties. You can take an empty spray bottle, add 5-7 drops of dish soap, and then add 2 cups of warm water. Shake the mixture and spray on the drain flies to kill them.
4. Using a Trap for drain Flies: This method is good if the infested place is your kitchen. Take a bowl and fill it with equal amount of sugar, water and white vinegar. Add 5 -10 drops of dish soap. Leave the bowl overnight beside your kitchen sink. The fragrance of this liquid will attract the drain flies and as soon as they land on it they will be immediately drowned and dead.