Fruit flies become a nuisance during the harvest season, swarming around overripe or rotten fruits and vegetables in homes, gardens and businesses. Though fruit flies don’t bite or sting, their swarming behavior is annoying and creates an unfavorable impression of your home or business. The flies may also contaminate food with harmful microorganisms. In addition to fruits and vegetables, fruit flies are attracted to fermented liquids such as beer. You can place beer traps wherever flies are a problem.
Pour an inch of beer into a clear glass or plastic jar to bait and drown fruit flies. For a no-kill trap, place only a few drops of beer in the jar.
Roll a piece of notebook paper into a cone shape and place it narrow-side-down in the mouth of the jar.
Set the jar wherever you notice fruit flies. The beer will attract fruit flies, who will fly into the paper funnel in search of food. Since flies can’t figure out how to escape, they will drown in the liquid or remain in the jar.
Replace beer every day or two. Release live fruit flies outside or pour liquid with dead flies outside. If you pour the liquid in your trash or down the drain, the beer may attract more flies to these locations.