Do horse flies fly into the house?
Do horse flies fly into the house?
Yes. Horse flies are attracted by indoor light and human odors and can fly in through open doors and windows.
Entry routes
- Open windows and doors — they are strong fliers and can easily enter.
- Unscreened vents.
- Following people in — they may slip in when you open the door.
- Balconies and patios — flies active there may enter through sliding doors.
How to prevent horse flies from entering
- Install screens on windows and doors — this is the most effective measure; choose fine-mesh materials.
- Check door and window seals — fill gaps with weather stripping.
- Reduce indoor light attraction — horse flies are active during the day and are attracted to light; draw light-colored curtains during the day to reduce attraction.
- Doorway protection — install fly-proof curtains or air curtains at the main entrance.
- Yard protection — spray areas around patios, balconies, and entrances with household hygiene insecticide containing permethrin to form a protective film.
What to do if they get inside
If a horse fly gets indoors, do not swat it directly with your hand, as their large size leaves messy stains. Use a fly swatter or electric swatter, or vacuum it up. You can also spray corners of the room with permethrin-containing insecticide; flies that land on treated surfaces will die.