To kill house flies, use a fly swatter for single flies, hang sticky fly paper or a UV light trap where they gather, and set homemade traps (apple cider vinegar or sugar water with a drop of dish soap, or a bottle trap with fruit). Then remove what’s attracting them—uncovered trash, food scraps, pet waste, and drains—and keep them out with window screens. If you suddenly see many flies, look for a hidden source like a dead animal or rotting food.
8 Ways to Kill House Flies
- Fly swatter: simple and effective for one or two flies. Approach slowly from behind.
- Sticky fly paper or ribbons: hang near windows, lights, and trash areas (out of reach of hair and pets).
- Apple cider vinegar trap: see the recipe below.
- Sugar water trap: mix sugar and water with a drop of dish soap in a jar.
- Bottle trap: cut the top off a plastic bottle, invert it into the base as a funnel, and add sweet bait.
- UV light trap: electric traps with sticky boards work well indoors at night.
- Fly bait stations: commercial baits for garages and outdoor areas (follow the label).
- Indoor fly spray: use sparingly, labeled for indoor flying insects, away from food.
Best Homemade Fly Trap (Vinegar and Dish Soap)
- Pour about ½ cup of apple cider vinegar into a jar.
- Add a teaspoon of sugar and a few drops of dish soap and stir gently.
- Cover with plastic wrap, secure with a rubber band, and poke a few small holes.
- Place near where flies gather and replace every few days.
Why Do I Suddenly Have So Many Flies?
- A dead mouse or bird in a wall, attic, or crawl space
- Rotting food in a trash can, under an appliance, or in a garbage disposal
- Pet waste in the yard or a litter box
- Open doors or torn screens during warm weather
- Fruit left out on counters (also attracts fruit flies)
How to Keep Flies Out
- Use lidded trash cans and take trash out often.
- Rinse recycling and clean bins regularly.
- Repair window and door screens.
- Pick up pet waste daily.
- Clean drains and garbage disposals.
- Keep fruit in the fridge or covered.
Traps vs Sprays
Pros
- Traps work continuously with no chemicals
- Homemade traps cost almost nothing
- Sprays kill flies instantly
Cons
- Traps take time and need replacing
- Sprays add chemicals near food
- Neither works if the breeding source isn’t removed
When to Call Pest Control
Call a professional if flies keep returning despite cleaning, you can’t find the source, or you suspect a dead animal inside a wall.
Frequently Asked Questions
How do I get rid of lots of flies in my house?
Find and remove the source first, then use several traps—fly paper, vinegar traps, or UV light traps—in the rooms where flies gather.
What is the best homemade fly killer?
An apple cider vinegar or sugar-water trap with a few drops of dish soap, covered with perforated plastic wrap.
Why do I suddenly have 20 flies in my house?
Usually a hidden breeding source such as rotting food, trash, or a dead animal, often combined with open doors or damaged screens.
What is the best fly killer for indoors?
UV light traps and sticky fly paper are effective and chemical-free. Use indoor-labeled sprays sparingly.
What smells keep flies away?
Strong scents like basil, mint, lavender, and eucalyptus may help a little, but cleanliness and screens work far better.
