How to get rid of flies in the house: quick fixes and the real cause

Step by step: how to get rid of flies in the house

1. 1

   Remove the flies already inside

   Swat flies when they land, or vacuum them off windows with the hose attachment, which is faster when there are many. Open one window on the shady side and close the blinds on the sunny side; many flies will head for the light and leave.

2. 2

   Set traps where they gather

   Hang sticky fly ribbons near windows and away from food, or use a plug-in light trap in the room where you see the most. Keep traps out of reach of children and pets and replace ribbons when they are covered.

3. 3

   Find out how they get in

   Walk around and look for torn or loose window screens, gaps under doors, a pet door that stays open, and doors propped open for long periods. House flies follow food smells in through any gap.

4. 4

   Repair screens and seal gaps

   Patch small holes in screens with adhesive repair patches and replace screens with larger tears. Add a door sweep to exterior doors with a visible gap at the bottom. Close doors behind you on warm days.

5. 5

   Clean up the trash area

   Take indoor trash out at least once or twice a week, more often in summer. Keep outdoor cans and dumpsters tightly closed and as far from doors and windows as you can. Wash cans with hot soapy water when you see residue or maggots in the bottom.

6. 6

   Pick up pet waste daily

   Bag dog droppings and seal the bag before it goes in the trash, and scoop litter boxes every day. Damp droppings are one of the main places house fly maggots develop.

7. 7

   Rinse recycling and manage compost

   Rinse cans, bottles and food containers before they go in the bin. Turn and cover a backyard compost pile and keep meat and dairy out of it, since a poorly kept pile can breed flies.

8. 8

   Check for a hidden dead animal

   If large, shiny blue or green flies keep appearing indoors, a mouse, bird or squirrel may have died in a wall, attic or crawl space. Follow the smell, remove the carcass if you can reach it, and seal the gap the animal used.

Why are there so many flies in my house suddenly?

A sudden swarm of large flies usually means something is rotting nearby, often a dead animal in the house, or a new outdoor source such as an overflowing trash can or a neighbor’s compost. A steady trickle usually means a gap in screens or doors.

Texas A&M AgriLife Extension explains that house flies rarely breed inside; they come in through open doors and unscreened windows. Blow flies and flesh flies, which are larger and often metallic blue or green, usually show up indoors a week or two after maggots develop in a dead animal in the structure, and they stop appearing within one to three weeks.

Small flies are different. If yours are tiny and hovering around fruit, plants or drains, see how to get rid of fruit flies, fungus gnats or drain flies.

What is the fastest way to kill flies in the house?

A fly swatter or a vacuum is fastest for a handful of flies; sticky ribbons and light traps handle a steady trickle. None of them stop new flies arriving, so pair them with the fixes above.

Should you use fly spray indoors?

Only as a last resort, and only a product labeled for indoor use, applied exactly as the label says. Sprays kill the flies in the air today and do nothing about where they come from.

UC IPM says eliminating the places larvae develop is the preferred way to control pest flies, that house flies are now resistant to many registered pesticides, and that insecticides should be used only for immediate control of adults. The National Pesticide Information Center gives the same advice and reminds you to read and follow all label instructions. The EPA’s citizen’s guide to pest control puts prevention and non-chemical controls first, and says to remove food, pots and pans and dishes before treating kitchen areas, keep pesticides off food preparation surfaces, and keep children and pets away from treated areas for at least as long as the label says. Never use outdoor or agricultural fly products inside the house.

How do you keep flies out of the house?

Deny them food smells and entry points: tight lids, clean cans, prompt pet waste pickup and intact screens prevent most indoor fly problems.

• The NPIC suggests keeping outdoor dumpsters at least 50 feet from kitchen doors and windows where you can.
• Fix leaking drains and garbage disposals, which attract several kinds of flies.
• Wipe kitchen counters and sweep up crumbs each evening; our kitchen cleaning checklist covers the daily basics.
• Feed pets indoors, or pick up outdoor food bowls once they have eaten.
• Keep screens on every window you open, including basement and garage windows.

Mistakes to avoid

• Spraying insecticide around the kitchen while the trash can outside the back door is open and full.
• Hanging sticky ribbons over the dining table or food prep area.
• Leaving dog droppings in the yard for days, where they breed maggots.
• Ignoring a sudden wave of big metallic flies, which often points to a dead animal in the house.
• Leaving a door propped open on a warm day “just for a minute”.