How to Get Rid of House Flies

To get rid of flies in the house, first remove what they breed in (open trash, pet waste, compost, or a dead animal) and close the gaps they use to get in, then kill the ones already inside with fly tape, a swatter, or a quick pyrethrin spray. If you only do the last part, new flies replace the dead ones within days.

House flies breed outdoors and in garbage, not in your walls, so control is mostly about sanitation and screens. Here is the order that works.

Step 1: Identify the fly

This plan is for house flies (1/4 inch, gray, striped back) and their larger relatives, blow flies. If yours are tiny, use the right guide instead:

• tan with red eyes, around fruit → fruit flies
• tiny and black, near houseplants → gnats
• slow, clumsy flies on fall or winter windows → cluster flies

Not sure? Compare on the house flies page.

Step 2: Remove the breeding source

A house fly lays eggs in moist, rotting material, and the maggots develop in about a week. Extension guides call sanitation the mainstay of fly control, so start here:

• Trash: use cans with tight lids, bag food waste, take it out at least twice a week in summer, and rinse the can monthly. Put bins away from doors.
• Pet waste: pick up dog waste daily; scoop litter boxes daily.
• Compost: keep it covered, bury fresh scraps under brown material, and do not add meat.
• Food: do not leave pet food out; clean up grill grease and spills.
• Dead animal: a sudden swarm of shiny green or blue blow flies in one room points to a dead mouse or bird in a wall, attic, or vent. Follow the smell, remove it if you can, and the flies stop within days.

Step 3: Keep flies out of your house

• Repair torn screens and fit screens on every window you open. Standard 18x16 mesh keeps house flies out.
• Add door sweeps and weatherstripping.
• Close gaps around window AC units, dryer vents, and pipes.
• Keep doors closed, especially near the grill or trash area.
• Use a screen door or a magnetic mesh curtain for doors that are often open.
• For cluster flies, seal attic and siding gaps in late summer, before they move in.

Step 4: Kill the flies already inside

Using spray safely. Indoor flying-insect sprays usually contain pyrethrins or synthetic pyrethroids. Remove or cover food, dishes, and pet bowls, keep people and pets out of the room until it airs out, and cover aquariums (these chemicals are highly toxic to fish). Always follow the EPA-registered label; the label is the law.

How to get rid of house flies with vinegar

A vinegar trap works best on fruit flies, but it catches some house flies too:

1. Fill a jar with an inch of apple cider vinegar and a spoonful of sugar.
2. Add one drop of dish soap.
3. Cover with plastic wrap and poke a few holes.

For house flies, a better homemade bait is a bit of overripe fruit or a little sugar water with a splash of fruit juice in a bottle with a narrow neck. Outdoors, baited fly traps with a commercial lure work very well, but they smell strongly; hang them 20 feet or more from doors so they pull flies away from the house.

What does not work

• Bags of water with pennies: no evidence they repel flies.
• Bug zappers indoors: house flies are weakly drawn to UV, and zappers can scatter insect fragments.
• Essential oil sprays and herb pots: at best a mild, short-lived effect.
• Foggers: kill some flies but do nothing about the source, and leave residue on surfaces.

How long it takes

If the source is gone and doors are screened, adults inside are gone in one to three days. If flies keep appearing for more than a week, there is still breeding nearby, possibly a dead animal or a neighbor's compost or dumpster.

When to call a professional

Call a pest professional if you cannot find the source, if there is a dead animal in a wall or crawl space you cannot reach, or if cluster flies come back every year. Pros can treat exterior siding and eaves before fall and set commercial-grade traps. A one-time service typically costs about $150 to $300 (approximate). Compare products in bug sprays.