House Flies in a Bar: How to Keep Them Out
Quick Answer: House flies mostly come in from outside and from the trash, so the fix is at the door and the bin. Oregon State Extension advises screens on windows that open, no propped-open doors, closed dumpster lids, rinsed cans and bottles, and clean soda dispenser drip trays. It says insecticide rarely clears an indoor fly problem. A screen pourer protects one bottle; it does not keep house flies out of a bar.
A house fly is not a fruit fly, and the fix is different. Fruit flies breed in ripe and fermenting food behind the bar, and our guide to fruit gnats versus fruit flies helps you tell them apart from other small flies. House flies mostly breed outside and walk in through the door. Oregon State University Extension says they can carry germs from garbage to food and food-preparation surfaces. Sources checked October 2026.
Is it a house fly or a fruit fly?
Judge it by size. Oregon State Extension (PNW 769) gives the house fly as about 1/4 inch (6 to 8 mm) long. Fruit flies are about 1/8 inch (3 mm) with transparent wings and bright red eyes. Drain flies are also about 1/8 inch, gray and furry. Each breeds somewhere different, so the fly decides the fix.
| Fly | Size | Where it breeds | First fix | Source |
|---|---|---|---|---|
| House fly | About 1/4 inch (6 to 8 mm) | Mostly outside, in garbage and decaying matter | Doors, screens, bins | PNW 769; PNW 770 |
| Fruit fly | About 1/8 inch (3 mm), red eyes | Ripe and fermenting fruit and vegetables | Remove the source (see where bar fruit flies come from) | PNW 769 |
| Drain fly | About 1/8 inch (3 mm), gray, furry | The film that builds up in drains | Clean the drain | PNW 769 |
How do house flies get into a bar?
Through doors left open and windows without screens. Oregon State says most larger flies invade from outdoors, and house flies usually become indoor pests when external doors are propped open or windows are not screened (PNW 770). The FDA Food Code 2026 (§6-202.15) says a food establishment closes gaps and uses tight-fitting windows and solid, self-closing, tight-fitting doors. Where windows or doors are kept open, it allows 16-mesh screens, properly installed air curtains or other effective means. Oregon State suggests 18 x 18 mesh screens and air doors with air currents of 1,500 ft/min (450 m/min) where possible. Your health department enforces the version of the code it has adopted. For the fruit fly side of a patio, see why fruit flies peak in summer.
What draws house flies to the back door?
The trash and the recycling. House flies breed in garbage and decaying matter, so what sits outside the door decides how many reach it.
| Where | What to do | Source |
|---|---|---|
| Outside bins and dumpster | Keep tight-fitting lids closed, keep the area clean, and do not go more than a week between pickups | Food Code §5-501.113 and §5-501.115; PNW 770 |
| Bin location | Place bins as far from entrances as is practical; 50 feet or more is ideal | PNW 770 |
| Recycling | Rinse cans, bottles and plastic containers before they go in | PNW 769 |
| Indoor bins | Clean them inside and out and empty them daily | PNW 769 |
| Soda dispenser drip trays | Check them for spills | PNW 769 |
What can a bar use to get rid of house flies?
Start with the table above, because insecticide alone rarely works. For fruit flies instead, see how to get rid of fruit flies in a bar. Oregon State says insecticide applications are rarely successful in eliminating indoor fly infestations and that the key is fixing the conditions where flies develop (PNW 769). For traps it recommends UV light traps with sticky capture boards over electrocution traps, which can aerosolize fly bodies and contaminate indoor areas, food and food-preparation surfaces. For house flies it says to place a trap within 20 feet of entryways, about 6 feet off the floor, with no competing light, and to leave it on continuously (PNW 770).
If you spray, the Food Code (§7-202.12) requires a pesticide label that states the use is allowed in a food establishment, applied so nothing drips, fogs or sprays onto food, equipment or utensils. Follow the label. Never spray over open bottles, garnish, ice or clean glassware, and ask your health department what applies to you.
Will a screen pourer keep house flies out of a bar?
No. A screen guards the pour opening of one bottle, not the room. A house fly can still land on the bar top, the rail, a glass or the garnish tray. Doors, bins and drip trays come first.
Where the Esatto Liquor Pourer with Screen, 12 Pack fits
Esatto makes and sells the Esatto Liquor Pourer with Screen, 12 Pack. It is our own product, not an independent pick. Its page describes a free-flow pourer with a built-in screen that acts as a protective barrier, keeping bugs and debris out of your liquor. That covers the opening of an open bottle between pours. The screen pourers collection lists the other pack sizes.
Frequently asked questions
How do I get rid of house flies in a bar?
Find where they enter and what draws them. Close and screen openings, keep outside bin lids shut, rinse recycling and check drip trays. Add a UV light trap with a sticky board near the entry. Oregon State says spraying alone rarely clears an indoor fly problem.
How do I keep flies away from a bar?
Keep doors from being propped open, screen windows that open, and put bins away from the entrance. Empty indoor bins daily and rinse cans and bottles before recycling.
What is the best way to get rid of flies?
Remove what they are breeding in, then block the way in. For house flies that means outside bins and open doors. For fruit flies it means ripe and fermenting food. Traps catch adults but do not replace sanitation.
How do I get rid of house flies naturally?
The extension pages cited here list no home remedy or repellent for house flies. Their non-chemical steps are the ones in this post: closed doors, screens, clean and covered bins, rinsed recycling and sticky UV light traps. Those do not rely on spraying.
Are house flies the same as fruit flies?
No. A house fly is about 1/4 inch long and breeds mostly outside. A fruit fly is about 1/8 inch with red eyes and breeds in ripe and fermenting fruit and vegetables. The fix differs, so identify the fly first.
Why are there flies outside my bar door?
Probably the bin. House flies breed in garbage and decaying matter. Oregon State says to keep dumpster lids closed, keep the area clean and place bins as far from entrances as is practical.