Frugal & Natural Pest Control: Fruit Flies & Ants Be Gone! Fruit Fly Trap. I've done this. It works! 1 quart jar 1 piece of paper, rolled up into a funnel tape apple cider vinegar small slice of banana Fill a quart jar with a 1/2 inch of apple cider vinegar and a small piece of banana. Roll up your paper into a funnel shape (larger at the top) and tape it in place. Place the funnel into your jar and make sure all the edges are secured shut with tape. You may have to adjust the size of your funnel to make sure it fits nicely into your jar. Place the jar where the fruit flies are flying around and let it go to work. You will be amazed at how well this trap works. The fruit flies will smell the fruit and climb inside, but for some odd reason they don’t fly back up the funnel to get out. When you have caught a good supply, place the entire jar in the freezer. After a short time that flies with die and you can remove the jar from the freezer and use it again without even removing the old contents. Use repeatedly until your fruit flies are eliminated.