To make a fruit fly trap, place a piece of fruit in the bottom of a glass or jar, and tape a paper funnel securely into its opening. This method attracts flies and prohibits them from escaping easily, according to Apartment Therapy.
In place of fruit in the bottom of a homemade fly trap, try using wine or vinegar. Apple cider vinegar works especially well to attract flies, suggests Apartment Therapy. When constructing the fly trap, be sure to make the paper funnel fit tightly, without any gaps, into the opening of the glass. This further prevents flies from escaping easily once inside.
A variation on this method involves adding a dab of dish soap to a jar of apple cider vinegar, according to Frugal Living Expert Erin Huffstetler at About.com. Flies are attracted to the vinegar but are unable to land on its surface. The addition of the dish soap disrupts the surface tension of the vinegar, and the fruit flies fall in and drown, Huffstetler explains. In the absence of a small glass or jar, use a bottle with a small neck.
Fruit flies enter the home when a bowl of fruit has been left on a countertop or a buildup of slime has occurred within drains, according to Orkin. Fruit flies lay their eggs in fruit or other sweet, decaying substances.