Over ripe fruit attract them bigtime … take the overripe fruit outdoors near the door … leave the door open for a minute or two. Most of them will follow the fruit. Close the door from the outside then trash the old fruit
amazon has a product , Aunt Fannie's Fruit Fly Punch, works great. It's a concentrated vinegar that the flies can't resist! You need to remove the home the fungus gnats are living -- I'm guessing you in Chicago during the winter have some house plants. The fungus gnats are living in the top soil. Get some diatimatious earth to top dress the soil. The gnats will dry out and die.
This is Linda and I found a list with a lot of different ways to get rid of gnats and fruit flies. Take a look at the link below to some ideas that should help you. :) Wishing you the best.