Are flies making your patio, deck, or garden unbearable? Pesky flies can quickly ruin an outdoor gathering or a peaceful afternoon. Instead of reaching for harsh chemicals or expensive traps, why not try a simple, effective, and budget-friendly DIY solution?
This homemade fly trap uses common household items to create an irresistible lure for flies, trapping them and helping you enjoy your outdoor spaces in peace. It’s easy to assemble, economical, and a great way to put an old plastic bottle to good use.
What You’ll Need
Materials
- 1 clean, empty 2-liter plastic bottle (e.g., soda bottle)
- 1 cup warm water
- 1/4 cup sugar
- 1 teaspoon active dry yeast
- 2-3 drops dish soap (optional, but recommended)
Tools
- Scissors or a utility knife (be careful!)
- Measuring cups and spoons
- Stirring stick or spoon
- Tape or staples (optional, for securing the funnel)
Why This DIY Can Be Useful
This DIY fly trap works by creating an attractant that flies find irresistible. The combination of warm water, sugar, and yeast produces carbon dioxide (CO2) and a sweet, fermenting scent. Flies are naturally drawn to these odors, which mimic decaying organic matter or ripe fruit.
Once flies enter the bottle through the inverted funnel, the design makes it difficult for them to find their way out. The optional dish soap helps to break the surface tension of the liquid, so flies that land on it are more likely to sink and get trapped, rather than being able to fly away.
How to Make It
- Prepare the Bottle: Using scissors or a utility knife, carefully cut the top third of the plastic bottle off. Make sure the cut is clean and relatively straight. The top part will form the funnel.
- Mix the Bait: In the bottom two-thirds of the bottle, pour in the warm water. Add the sugar and stir until it dissolves completely.
- Add the Yeast: Sprinkle the active dry yeast into the sugar water mixture. Do not stir it too vigorously at this stage; just let it sit.
- Add Dish Soap (Optional): If you are using dish soap, add 2-3 drops to the mixture. This will help trap flies by breaking the surface tension.
- Assemble the Trap: Take the top part of the bottle you cut off and invert it, placing it upside down into the bottom section of the bottle, creating a funnel. The cut edges of the top part should rest inside the larger bottom part.
- Secure (Optional): You can use tape around the seam or staple the edges together to secure the funnel in place, especially if you plan to hang the trap.
How to Use It
Place your DIY fly trap in areas where you notice the most fly activity. Good spots include near your patio or deck, outside doorways, in the garden, or near trash cans.
- Placement: Position the trap a few feet away from where people are congregating. The idea is to attract flies away from you, not right next to you. Placing it in a partially shaded area can help prevent the liquid from evaporating too quickly.
- Check Regularly: Check the trap every few days. When it fills up with flies or the bait loses its effectiveness (usually within 1-2 weeks, or sooner in hot weather), it’s time to empty and refill it.
- Emptying: Carefully pour the contents into a sealable bag or container before disposing of it in the trash. Rinse the bottle thoroughly before refilling with fresh bait.
What to Expect
This DIY fly trap can be quite effective at reducing the number of flies in your outdoor areas. You should notice fewer flies buzzing around after a day or two of placing the trap. Keep in mind that it’s a tool for reduction, not complete eradication, and its effectiveness can vary depending on the severity of your fly problem and local conditions.
Flies are attracted to the bait, so it will draw them to the trap. This is why placement a little distance from your main gathering spots is key.
Helpful Tips
- Multiple Traps: For larger outdoor spaces or more severe fly problems, consider making and placing several traps around the perimeter of the area you want to protect.
- Experiment with Bait: While sugar and yeast are effective, some people find success by adding a small amount of fruit juice, overripe fruit, or vinegar (apple cider vinegar can be especially attractive) to the mixture.
- Hang Them: If you secure the funnel, you can punch a couple of holes near the top edge of the larger bottle section and thread a string or wire through to hang the trap from a tree branch or hook.
Important Notes / Safety
- Sharp Edges: Be very careful when cutting the plastic bottle. Use a stable surface and cut away from your body.
- Disposal: When emptying the trap, be aware that it will contain deceased flies and a fermenting liquid. Dispose of the contents responsibly and hygienically.
- Attraction: The trap is designed to attract flies, so ensure it’s placed in an area where this attraction is beneficial (drawing them away from people) and not a nuisance.
- Pets and Children: While the ingredients are generally safe, keep the trap out of reach of curious pets and small children to prevent accidental ingestion or spills.
