Pour vegetable or olive oil in your kitchen sink. This will catch any gnats that hang around the drain or garbage disposal. The gnats will fly into the oil but will be either unable to free themselves from it, or simply unable to mate afterward, as they are coated in the oil. You may need to repeat this process several times to get all of the gnats, but it is very effective.
Our trick for getting rid of fruit flies is simple: put three drops of dish soap (whatever kind you use) into 1 cup of vinegar and leave it out in a bowl. The vinegar will attract the flies to the bowl and the soap will reduce the surface tension so the flies sink to the bottom.
I can’t stand those pesky gnats that sneak into my house at least once each summer. Because we don’t use any chemicals in the kitchen, I needed to find a natural way to get rid of them. After searching online, I found a few easy recipes that utilized things I already had on hand.