The small brown, red-eyed fruit fly is usually carried inside homes in fresh fruits and vegetables, most often bananas. The items in which the flies are breeding must be found and discarded in the outdoor trash. To deal with the remaining adult flies, create a trap by pouring a few ounces of vinegar into a cup and covering the cup with a plastic wrap secured with tape or a rubber band. Poke a hole about 1/8 to 1/4 inch through the plastic. Place the trap in rooms where the flies are seen. The flies enter through the opening but have difficulty exiting, eventually drowning in the vinegar.