A few simple household ingredients can kill flies just as effectively as store-bought products. The best approach depends on which flies you’re dealing with and whether you want to trap them, stick them, or spray them down. Here are the most reliable homemade methods, how they work, and how to get the best results from each one.
Apple Cider Vinegar Traps for Fruit Flies
Apple cider vinegar is the gold standard bait for fruit flies because it contains the same fermentation compounds found in overripe fruit. Pour about 1/4 cup of apple cider vinegar into a jar, then add one or two drops of liquid dish soap. The soap breaks the surface tension of the liquid, so when flies land to drink, they sink and drown instead of standing on the surface. Stir gently to distribute the soap evenly without creating a layer of bubbles that might warn flies away.
You can boost this trap’s effectiveness with a simple entry barrier that prevents flies from escaping once they’re inside. There are a few designs worth trying:
- Paper cone method: Roll a piece of paper into a funnel shape and insert it into the jar opening, narrow end down. Flies follow the scent through the small opening but struggle to find their way back out.
- Plastic wrap method: Stretch plastic wrap over the jar, secure it with a rubber band, and poke a few small holes with a fork. Flies enter through the holes and get trapped inside.
- Punched lid method: Use a Mason jar with a metal lid and punch tiny holes using a hammer and nail.
A leftover wine bottle works too. Leave the last quarter-glass of wine in the bottle, add a drop of dish soap, and set it out. The narrow neck acts as a natural funnel. No prep required.
Outdoor Traps for House Flies
House flies are a different problem than fruit flies. They’re larger, stronger fliers, and attracted to protein and decay rather than sweet fermentation. For outdoor house fly traps, bait with something that smells terrible: a small piece of raw shrimp, meat scraps, or fish works well. Place the bait inside a container with a funnel entry (a cut plastic bottle inverted into its own base is the classic design) so flies can get in but not out.
Place these traps away from where you actually spend time. The goal is to draw flies in the opposite direction, not to lure them closer to your patio or door. Hang them near walls or fences at a distance from dog runs, seating areas, and chicken coops. Be aware that the smell can also attract animals. Feral cats and raccoons have been known to knock over or tear into outdoor fly traps, so hanging them on a wall or hook rather than setting them on the ground helps.
Where to Place Indoor Traps
Placement matters more than most people realize. Flies are most active and most responsive to traps below five feet, often skimming close to the floor. A trap sitting on a countertop or table will outperform one placed on top of a refrigerator or shelf. Position traps near the pathways flies use to move through your home: doorways, windows, and the space between your kitchen and any entry point.
Avoid placing traps in direct sunlight or right next to bright windows, since competing light sources can reduce a trap’s draw. And never put a lit or glowing trap where its light shines out through a door or window after dark, because you’ll attract outside insects into your home.
Homemade Fly Spray
If you want to repel flies rather than trap them, a simple spray bottle mixture can help. The most basic version uses two cups of apple cider vinegar, one cup of water, and a squirt or two of dish soap. The soap helps the mixture cling to surfaces instead of beading up and rolling off. Spray it around doorframes, windowsills, and anywhere flies tend to gather.
Adding essential oils significantly improves the repellent effect. Thyme oil is one of the most effective against common house flies. Citronella, lemongrass, peppermint, and lavender also work well. A more potent recipe combines one cup of white vinegar, two cups of water, two tablespoons of liquid soap, 50 drops of citronella oil, 25 drops of lemongrass oil, 25 drops of peppermint oil, and 20 drops of lavender oil in a 32-ounce spray bottle. Shake well before each use, since the oils and water will separate between applications.
One useful trick: alternate between different formulas every time you mix a new batch. Switching up the scent profile seems to keep flies from acclimating to a single repellent.
DIY Sticky Fly Paper
Homemade fly paper is surprisingly easy to make and catches both house flies and fruit flies passively. The basic idea is soaking strips of paper in a boiled sugar mixture that stays permanently tacky.
Cut a brown paper grocery bag into strips about one to two inches wide and eight to twelve inches long. Punch a hole in the top of each strip and thread a piece of string through for hanging. Then make the sticky coating: combine equal parts sugar, honey (or corn syrup), and water in a small saucepan. Heat over low heat, stirring until the sugar dissolves and the mixture thickens into a syrupy consistency. Don’t let it boil too hard or it will harden like candy instead of staying sticky.
Dip each strip into the warm mixture, coating both sides. Let the excess drip off over newspaper for about 30 minutes, then hang them near windows, on a porch, or anywhere flies congregate. A variation uses 1/4 cup maple syrup, one tablespoon brown sugar, and one tablespoon white sugar, with the strips soaked overnight for a deeper coating. Either approach produces strips that stay tacky for days in dry conditions, though humidity can eventually break down the stickiness.
Matching the Method to the Fly
Fruit flies, the tiny ones that hover around bananas and drains, respond best to vinegar-based liquid traps. They’re drawn to fermentation and will find even a small jar of apple cider vinegar within hours. House flies, the larger ones that buzz around rooms and land on food, are better targeted with sticky paper, repellent sprays, or protein-baited traps outdoors. Drain flies, the fuzzy moth-like flies near bathroom sinks, won’t respond to vinegar traps at all. They breed in the organic film inside drainpipes, so the fix is cleaning the drain with a stiff brush and flushing it, not setting traps.
Fungus gnats, the tiny flies that rise from houseplant soil, are best caught with yellow sticky traps placed at soil level (you can coat small yellow index cards with the homemade sticky mixture above). They’re attracted to the color yellow specifically, so the trap color matters more than the bait.
For most kitchens dealing with a summer fruit fly invasion, the vinegar and dish soap jar is the fastest and easiest starting point. Set out two or three small jars, replace the vinegar every few days as it loses potency, and you should see a major reduction within 48 hours.