The most popular home remedy is the vinegar bottle trap. Fill a bottle almost till the top with vinegar and close it. Poke several holes inside the cap and place it at a strategic corner or a place where you think the gnats are breeding. Gnats are attracted to the smell of vinegar; they will climb into the bottle through the holes but won’t be able to climb out. This method is very effective and you can place many such traps in the house.
In a bowl, mix some vinegar with a little bit of dish soap. The vinegar will attract the gnats and they will climb into the bowl. The dish soap will cease friction and even if the gnats try to wriggle out, they will keep slipping inside.
at 2:10 AM on Jun. 18, 2011