Things You'll Need
Sweet red wine
Small chunks of fruit
Fruit flies, sometimes called fruit fly gnats, are tiny insects that reproduce on ripe fruits and vegetables. Because they have a short lifespan and lay many eggs, fruit flies can take over your kitchen before you realize what's happening. These pests are attracted to sweet liquids, so you can use a bottle of sweet red wine to lure them into a homemade fly trap. Once you've conquered the infestation, you can prevent recurrences by keeping your kitchen clean, washing out your garbage disposal frequently, storing ripe fruit in the refrigerator and taking out the trash regularly.
Pour some or most of the wine out of the bottle. You only need an inch or two of liquid at the bottom of the bottle for the trap to work.
Insert a few small pieces of fruit into the bottle, such as strawberry, banana or orange slices. Make sure the fruit falls all the way to the bottom, into the remaining wine. Wine on its own isn't always sweet enough to attract fruit flies, so adding pieces of fruit increases the trap's effectiveness.
Roll a sheet of paper into a cone shape. Insert the tip of the cone into the top of the bottle. Adjust the paper until it fits snugly into the bottle, without leaving a gap between the paper and the glass. Tape the paper to itself so it keeps this cone shape. Trim off the top of the cone with scissors if there are more than about 6 inches of paper protruding above the bottle.
Place the bottle on a counter or table in the kitchen or wherever you have the biggest fruit fly problem. Let it sit for several days or until you stop seeing fruit flies in your home. Take the bottle outside, holding it upright carefully, and empty it into the trash.
A dish or jar containing juice, cider vinegar or beer works equally well. If you use a liquid that doesn't contain alcohol, add a few tablespoons of alcohol or dish-washing soap to the trap. These substances break the surface tension of the liquid and make the flies more likely to drown; they also act as a poison for the flies and their eggs