I have a problem with gnats in my house. Is there a DIY solution?

place bowls of apple cider vinegar covered with saran wrap,poke some holes in the top

Poor Clorox down all drains then cover up the drain

This is a common problem this time of year I have them too. Take a bottle or jar and put a couple of inches of apple cider vinegar into the bottom make a cone out of paper and put in the top of the bottle. They are attracted to apple cider vinegar, fly in, and are trapped. Keep all of your counters clean, pour bleach down your drains. And take your garbage out on a regular basis. I wish there was some overnight method to get rid of them unfortunately there's not.

Spray all your drains with Simple Green. They live in the sink drains. They will move to other drains when sprayed, so be sure to spray all drains in the house twice a day until you do not see them. Then do it once a week for maintenance. Be sure all fruit is refrigerated or in plastic wrap. Simple Green is in the auto/boat/camping area of Walmart in concentration, but I use it all yr round for cleaning as it is non-toxic. It is also in Menards in spray bottles as well as concentrate where they sell soaps and detergents. I even killed a fly that landed near my sink when I happened to have the bottle in my hand. It is both a disinfectant and deodorizer.

i put small glass of vinegar on window sill and they go for it and drown. Takes a while to get them all but it works.

Our bug man says to put bleach in all the drains. I use about 2 tablespoons in all my drains about once a week at night before I go to bed so it sets in the drain overnight. Should help with the problem. But I will be trying the apple cider solution above also.

Probably drain flies do what Penny said...