How to Get Rid of Flies: Find the Source and Stop Them for Good

Written by Paul Hayes

Swatting flies and spraying the air feels productive, but the flies keep coming because you are fighting the symptom, not the cause. Every fly in your home hatched from a specific breeding source nearby: a trash can, a drain, a bowl of fruit, a houseplant, or even a dead mouse in the wall. Find and remove that source and the flies disappear. Skip that step and you will be swatting forever.

The short answer: identify which fly you have, because that tells you where it is breeding. Then remove the source (clean the drain, toss the fruit, empty the trash, dry out the soil, or find the dead animal), trap the adults that remain, and seal up the gaps and screens that let them in. Sanitation does ninety percent of the work; sprays and traps just clean up what is left.

Identify the Fly and Where It Breeds

The single most useful thing you can do is figure out which fly you are dealing with, because the breeding site, and therefore the fix, is different for each one.

Fly Looks like Breeds in The fix
House fly Large, dull gray, four stripes on the back Garbage, pet waste, manure, rotting organic matter Sanitation and lidded trash
Fruit fly Tiny, tan, often red-eyed Overripe fruit, drains, recycling, damp mops Remove fruit, clean drains, vinegar trap
Drain fly Small, fuzzy, moth-like The slimy organic film inside drains Scrub the drain, not just bleach it
Fungus gnat Tiny, dark, weak flier near plants Moist houseplant potting soil Let the soil dry out, sticky traps
Cluster fly Large, sluggish, gathers at windows Outdoors in lawns (larvae develop in earthworms); overwinters in your walls and attic Seal and exclude, vacuum, not a cleaning issue
Blow fly Shiny metallic green or blue Dead animals and carcasses Find and remove the dead animal

Not sure what you have? Our guides break down small black flies in the kitchen, fruit flies vs. gnats, and the small black flying bugs that are not fruit flies. A clue worth knowing: shiny metallic flies showing up indoors for no reason often mean a dead rodent or bird is tucked in a wall or attic.

The One Rule: Find and Remove the Source

Adult flies are the part you see, but they are a small fraction of the problem. A female can lay hundreds of eggs, and they go from egg to adult in about a week in warm weather, so a hidden breeding site refills the air faster than you can swat. Killing adults without removing the source is like bailing a boat without plugging the hole. Walk the house and track down what is feeding them:

  • Kitchen and trash: take out the garbage, scrub the can, wipe up spills and crumbs, and run the disposal. Toss or refrigerate overripe fruit and rinse recycling. Maggots in the bin are fly larvae, so clean the container completely. See our guide to getting rid of maggots.
  • Drains: if the flies are the fuzzy, moth-like kind, the breeding site is the gunk lining your drain. Bleach runs straight past it, so you have to physically scrub the pipe with a brush. Our drain fly guide walks through it.
  • Houseplants: tiny gnats hovering around plants are breeding in wet soil. Let the top inch or two dry out between waterings and add sticky traps. See gnats in the house and the dark-winged fungus gnat.
  • A dead animal: a sudden burst of large flies with no food source usually points to a dead rodent in a wall, attic, or crawl space. Find and remove it, and the flies stop. Our blow fly and flesh fly guides cover this.

How to Get Rid of Flies, Step by Step

1. Remove the breeding source

Do the detective work above first. This is the step that actually ends the problem, and everything else is cleanup.

2. Clean and deny them food

Flies are drawn to food residue, sugary spills, and moisture. Keep counters wiped, dishes washed, trash lidded, pet food picked up, and pet waste cleaned from the yard daily. The less there is to land on and feed on, the fewer flies stay.

3. Seal them out

Repair torn window and door screens, add door sweeps, and keep doors shut, especially at dusk. Cluster flies in particular get in through gaps around windows, eaves, and utility lines in fall, so sealing those openings is the real fix for them rather than any spray.

4. Trap and kill the adults that remain

Once the source is gone, mop up the survivors. A fly swatter and sticky fly ribbons handle small numbers. Indoor ultraviolet light traps quietly draw and catch flies in kitchens and garages. For fruit flies, a simple apple cider vinegar trap works well: pour vinegar into a cup, add a drop of dish soap to break the surface tension so they sink, and cover with plastic wrap poked with a few holes. For outdoor pressure, baited fly traps and residual sprays help, but place baited traps well away from doors so you are not drawing flies toward the house.

Do Natural Fly Remedies Actually Work?

Some DIY methods earn their reputation and some are pure folklore. Here is an honest read.

Method What to expect Verdict
Apple cider vinegar trap Genuinely effective for fruit flies; the scent lures them and a drop of dish soap makes them sink instead of landing and escaping Works for fruit flies
Herbs and essential oils (basil, mint, lavender, eucalyptus, lemongrass) Lab studies show these oils really can repel flies, but the few drops people use at home dissipate too fast and too weakly to clear an infestation Mild, short-lived
Bag of water over the door A widely shared trick with no scientific support; testing found no repellent effect, and one study found it can actually increase fly activity Myth
Venus flytrap or other carnivorous plants Catches the occasional fly but nowhere near enough to control a population Novelty only

If you want to try scents, our guide on scents that keep flies away covers the options, but treat them as a minor add-on to source removal, never a replacement.

Are Flies Dangerous? A Quick Health Note

House flies are more than a nuisance. They feed on garbage, waste, and decaying matter, then land on your food, where they can mechanically transfer bacteria like Salmonella and E. coli by walking on, regurgitating on, and defecating on surfaces. That is reason enough to keep them off food and out of the kitchen, though a few flies are not cause for alarm. Biting flies such as horse flies and the ones in our deer fly guide are a different, outdoor problem, and most gnats are harmless.

When to Call a Professional

Most fly problems are a do-it-yourself job once you find the source. Call a pro when the infestation is large and you cannot locate where they are breeding, when cluster flies return to the same attic or wall void year after year, or when a steady stream of blow flies points to a dead animal you cannot reach inside the structure. A professional can locate the hidden source and treat voids you cannot access.

How to Keep Flies From Coming Back

  • Keep trash in lidded cans, take it out regularly, and rinse recycling before it sits.
  • Wipe counters and spills, wash dishes promptly, and store ripe fruit in the refrigerator.
  • Clean drains periodically so organic film never builds up.
  • Pick up pet waste daily and keep compost turned and away from the house.
  • Repair screens, add door sweeps, and seal gaps around windows, eaves, and utility lines before fall to keep cluster flies out.
  • Do not overwater houseplants, since soggy soil breeds fungus gnats.

Related Fly and Gnat Guides

Frequently Asked Questions

What instantly kills flies?

A fly swatter, a contact aerosol fly spray, or a UV light trap kills adult flies quickly. But instant kills only deal with the flies you can see, so unless you also remove the breeding source, more will keep emerging within days.

What is the fastest way to get rid of flies?

Find and remove the source first, whether that is the trash, a drain, fruit, soil, or a dead animal, then trap the remaining adults with sticky ribbons, a UV trap, or a vinegar trap for fruit flies. Source removal plus trapping clears most problems in a few days.

Why do I suddenly have so many flies in my house?

A sudden swarm almost always means something is breeding nearby: an overflowing trash can, a dirty drain, forgotten fruit, overwatered plants, or a dead rodent in a wall. The number tells you the source is active, so go find it rather than reaching for the spray.

Does apple cider vinegar get rid of flies?

It works as a trap for fruit flies. The vinegar smell lures them into a cup, and a drop of dish soap breaks the surface tension so they sink instead of escaping. It does little for house flies or cluster flies, which are better handled by sanitation and exclusion.

Why are there cluster flies on my windows in winter?

Cluster flies overwinter inside wall voids and attics and drift toward windows and warmth on mild days. They are not breeding in your home and it is not a cleanliness issue, so the fix is sealing entry points and vacuuming up the ones that appear, not cleaning or spraying.

Paul Hayes
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