Quick and Easy Homemade Fly Trap

by Sarah TheHealthyHomeEconomist

homemade fly trapOne of the more popular posts on this blog is a nontoxic, homemade fly repellent made with – believe it or not – a penny, some water and a heavy duty zip lock bag.

I learned about this trick at a local farm during one of my children’s field trips and it works extremely well for repelling the type of flies in my neck of the woods here in Central Florida.

Reading through the comments on that post, however, it is apparent that not all flies from around the world are similarly repelled by the flybag trick!

Some folks swear by it and others deride it as ineffective. If you are one of the folks for whom the flybag isn’t working, I thought I would post another flies begone tactic for you to try, this homemade fly trap courtesy of my goat milk farmer who uses it with fantastic success.

homemade fly trap step 1As you can see, the homemade fly trap obviously works well as the picture above of one of the traps near my farmer’s house is loaded with several inches worth of dead flies!

The trick to this homemade fly trap is that it actually catches and traps the flies rather than repelling them like the flybag approach.  The flies get lured into the trap by a potential food source and can’t escape. When the fly trap becomes full of flies, you throw it away and make another one, or two, or three!

Make Your Homemade Fly Trap in 3 Simple Steps

The only supplies you need to make your homemade fly trap are a clean, empty 2 liter plastic soda bottle, some heavy duty packing tape, and some rotting produce. I recommend potatoes as they work really well for my farmer.

The pictures to the right illustrate how to quickly make your homemade fly trap:

  1. homemade fly trap step 2Cut an empty 2 liter soda bottle in two. The bottom half should be larger than the top. Making the cut about 1/4 – 1/3 of the way down the bottle works well (see photo).
  2. Remove the cap from the top of the bottle and turn it upside down. Place a few pieces of cut up, rotting produce in the bottom half of the bottle and then, place the upside down, open end of the bottle inside the bottom half (see photo).
  3. Tape the two halves of the bottle together so they stay secure.

homemade fly trap step 3Note that the better the bait, the more effective the homemade fly trap will be.  Here in Florida, potatoes that are soft and starting to rot work extremely well.  Any type of decomposing fruit or vegetable would work too – you can try different ones and see which attract flies in your locality most effectively.

Because you are using rotting food to attract and trap the flies, make sure you place the homemade fly trap in a place where the smell won’t bother you and will attract the flies away from the area you are trying to keep fly free.

Let me know if you have tried this approach where you live and what you use as bait inside the soda bottle. Did you find it worked well? Why or why not?

Sarah, The Healthy Home Economist


More Information

Nontoxic Pest Control Ideas that Work

Fast and Effective Fly Repellent

Safely Get Rid of Carpenter Ants in a Snap

Natural Fire Ant Killer That Works FAST

Attracting and Using Ladybugs for Garden Pest Control

Natural Flea Infestation and Prevention Strategies

Spider Repellent Guaranteed to Work

Fast Acting Mosquito Bite Remedy That’s Probably Already in Your Kitchen


Comments (53)

  1. From my experience these homemade traps don’t really work for reducing a mosquito population in a yard. I much better prefer professional mosquito traps that lure mosquitoes by imitating a human breath releasing carbon dioxide, which are a lot more expensive but also much more effective.

  2. Hi. I’ve used this type of bottle trap to catch wasps outside near the house. Everyone in our house is severely allergic &/or very phobic, so we wanted to keep our house’s small deck useable for us. First yr we baited it with some partly cooked meat in a small amt of water with unscented dishsoap, and hung it in a tree a couple meters/yards away from the porch. The water evaporated quickly, but there were a few dead wasps in it by then, and it seemed to work better for them with the dead ones as bait. (Are wasps canabalistic? Never heard, but it made me wonder.) Since then at the beginning of the season I make a new trap, baited with just meat, then let them act as bait for the others for the rest of the season. Not 100%, but it does noticeably help reduce the wasps.

    Never thought of that type of trap for flies until recently however, after we had to switch to wet cat food only for our cats for health issues, and had problems with flies attracted since. Because they seem drawn to the cat food, I’m going to try using a combo of wet cat food added to other fly bait recipes I’ve seen until I find a combo that works… I hope.soon! But if the effectiveness I saw with wasps is any indication, if I can find the right bait, it should be good..

    What someone else said about flies having compound eyes – I’ve read that too, and that it results in them only seeing motion & light, and they are drawn to light, so I suspect this type of trap would probably work best if made from transparent bottles rather than tinted ones.

  3. That’s so weird that the flies can’t figure out how to get out of the bottle once they’re inside.
    Or do they just love the rotting potato so much that they don’t bother trying to escape?

  4. Ive seen plenty if ideas for fruit flies and house flies but does anyone kniw what kind of attractant would work for.horse flies.and deer flies? We live in the forest and these pesky insects are swarming my poor horses weve tried several home made insect repellants with no luck and.commercial bug repellant works.good for mosquitoes and sand flies but doesn’t seem to phase the horse and deer flies

  5. Tried the bag of water and penny trick last year and no effect. It seemed to attract the flies. Will definitely try this one. My boyfriend collects every soda bottle we ever use so it is time to put them to good use. LOL

  6. We’ve used this method as well and it really works! Another very good source for eliminating flies is the QuickBayt Fly Bait product. It’s considered the best fly repellent for horses on the market. All you do is sprinkle the granules throughout the stable and ground and the flies will literally die within a minute of consumption. Hundreds a day!

    Your cheapest source online is at BugRepellentZone.com: http://bugrepellentzone.com/flies/quickbayt-fly-bait-fly-repellent/

  7. I’m from Australia and my greatest sucess in catching flies in a similar trap is to use a piece of beef kidney (about plum size) “ripened” in the fridge for about 2 weeks. Put kidney in trap and pour in 2 inches of water. I did this outside and the flies were sparming around in seconds!!

    • Greetings, fellow Oz dweller! I was using a bit of Kefir . . . had to stop . . oh my!! Fly Apocalypse. They liked it too much – flies got way out of control. Previous to that I was using the bottle trap with powder mix from Bunnings with success. (stinky stinky) I have just come inside from hanging up ziplock bags with water and a NZ copper coin inside. (Curses to the fact we have none of our own any more). I could be imagining it but I feel that the flies are decreasing already. I have put six up around the outside of the house: front, back, and both ends of the clothes line. Here’s to the end of the great Aussie Salute ^_^

  8. I live in Australia and as the aussie know, we have billions of the critters…I have tried this 2 litre bottle trap so many times using a heap of different attractants and nothing works….it wont even catch one fly.
    Ive used sugar syrups, oil and fat from the BBQ, cooked mince meat, fruit, blood and bone mixed with water, I even tried dog poo…..nothing works…I don’t know why it wont work as Ive read so many different articles saying how good these traps work.

      • Mags,

        I’ll have to give it a go in Brisbane! It’s gunna be hard to sacrifice my favourite spread ! Flies don’t deserve that lovely vitamin B.


    • I just tried this for the first time, using fresh strawberries. For the first few days it only trapped a handful of flies. But once the berries started to break down, the trap/bait really worked. The day mold first started appearing on the berries it went from a few flies to a whole swarm inside the trap. It’s quite satisfying to see so many of the little buggers trapped in there :)

    • It is essential that all outer surfaces of the bottle be absolutely clean. A tiny drop of food is a feast to a fly and they have no reason to enter the trap if it is available on the outside.

      I use a little rotting fruit, sugar water, yeast, and stale beer or wine. Some folks add vinegar, but I figure the mixture makes its own.

      Works a charm.

  9. Great post… After a nice day outside, some pesky fies got inside and are driving me nuts! Lol! I’ll try this today!

    About the fly’s inability to escape… As I read the responses above, I suspected that it had to do with a tidbit I remembered learning about as a kid, about the fly’s eye being “compound”. If you’ve seen photos of flies, you know what I mean, the eyes seem to be made up of many eyes! I googled it to make sure I was remembering it correctly before posting my reply (lol, I’m particular about being accurate! Lol!) and I came across some interesting info that explains why the trap works so well…

    A fly’s vision works in a very unique way. Because of their compound vision, their focus isn’t very good. They are very sensitive to motion, which is why they fly away before getting swatted, as well as having other “visual” (to them) sensitivities, but they can’t see very clearly in the way we do. In fact, they really don’t experience sight the way we do at all. So, based on what I read, it seems reasonable to assume that once they get in, they don’t even realize there is a way out, because they can’t see it! (Woo hoo! Gotcha sucka!!) I didn’t check on wasps, but I imagine their vision works in a similar manner, explicating why the traps work on them as well.

    Sorry this is long, but I hope this info on flies’ vision is helpful in your mission to kill these nasty pests! It’s pretty interesting, and reading up on it may even help with swatting efforts for the truly frustrated, like me! Lol!

    Again, great post on the trap! Excited to make mine right now!!

    • The way a fly sees also helps with what I read about a long time ago – “the sweet swat”. You position your hands above and to either side of the fly. When you bring your hands together, the fly flies upward and gets caught between them. With practice, you can judge just how high you need to place your hands to get the timing right…

    • Lorin,

      Yours is the best answer ever! No one else has provided this scientific fact on about why flies just seem to crawl out the same hole they came in on. Even the itty bitty gnats get stuck!

      Good on ya!


  10. Blow flies and bush flies go for a meat bait. You get maggots, which also die – it makes great garden fertiliser eventually. Fruit flies like the sugar & veges. The traps work best if you can put a light-proof lid over the top. Flies go upwards to the light. You want them to get caught around the top edges, not to see that there is a way to the light up through the funnel.

  11. You ask – why can’t the flies escape? I think the inverted-cone top is the secret. When the flies want to fly away they will encounter the sides of the trap and tend to fly or crawl upward, which leads them to a dead end between the bottle and the inverted cone. A normal bottle with an upright conical top will tend to funnel them toward the top hole, and escape.

    Another secret I think is the clear sides of the trap, which make the flies want to fly away toward the light. I’ll bet if the sides were opaque, they would find their way out by going to the only source of light, the hole, even if the top was upsaid down. Hey, that might make a good science-fair experiment!

  12. A successful fig tree grower once told me about cutting a whole in the side if a milk jug and putting 1 cup apple cider vinegar, 1 cup sugar, enough hot water to dissolve the sugar. I think a similar combination would be good for this idea. Just scale down the amount.

  13. I have used a coffee cup and mason jars before. But I use Plastic wrap over the top with about an inch of apple cider vinegar in the bottom. I use a small knitting needle to poke a few holes in the plastic wrap and in a few days, you won’t believe how many are trapped or floating on the cider. I have tried different things before, but the plastic wrap and apple cider have been the best combination!!!

  14. This is a great idea, and reminded me of the old joke: “Time flies like an arrow, but fruit flies like a banana.”

  15. I am curious as to what stops the flying beasts from flying back up through the opening of the plastic bottle that is upside down.they obviously access the food in the bottom from it ?

    • They apparently cannot figure out how to escape! Something similar to this traps wasps also, although I allow wasps to exist nearby because they are such beneficial creatures.

    • I think it has to do with their vision and equilibrium. For some reason they forgot how they got in the trap, because with these types of traps the flies always try to escape from the sides. Flies never fly straight up, which is what they’d have to do in order to get out of the trap. they fly in a horizontal or diagonal line. And for some reason they are too stupid to figure out they can just walk back up the spout

  16. Thank you so much for the very timely info! My daughter and I spent the day going in and out back kitchen door to bring in veggies ( for fermenting, of course ; v)within 2 days we had thousands of fruit flies! Tried fly paper ribbons, but they were mainly around the sink. Going to try ever tip listed, using banana, because they covered my ripe bananas. Don’t have any 2 liter bottles, but will try w/ some plastic water bottles I have from our last vacation. Hope it works because hubby is wanting to buy a can of Raid! I said no way!
    Thanks, as always, love your site!
    Sharon, Keller, TX

  17. Sarah, The Healthy Home Economist July 15, 2013 at 6:35 pm

    On a side note, it seems that the Coke Zero bottle above filled with dead flies is an appropriate use for this product, don’t you think?

    • Ha, you are too funny! In the time it took me to write 2 posts to you, the fruit flies have been literally cut in half!! Used over ripe banana and 3 plastic water bottles. THANK YOU!

      Sharon in Keller TX

  18. I have been using a similar method for fruit flies; with a canning jar and a plastic baggie inserted in and folded over around the opening, held down with a rubber band. I cut a very small hole in one corner of the baggie before putting it into the jar. I used beer as the attractant.

    • It was the same principle, Mason jar and a funnel made out of paper. They didn’t have two liter plastic bottles back then.

  19. I HATE FLIES!!!!! Hate Hate Hate Them!!!! Gruesome, filthy critters!!! But as much as I HATE flies…..I HATE mosquitos MORE!!!!! They are scary…esp with all the stuff they carry now days. I bet this idea with meat would work, too. I read about those Tiger mosquitoes and they don’t let go once they bite….WOW!!!

  20. I tried the bottle trick using apple cider vinegar, but it didn’t work for me. I tried the apple cider vinegar in a small plastic square container and added a drop or two of dish soap. The dish soap is supposed to stick to their wings and prevent them from flying. It worked well with the fruit/sewer flies, but not with the house flies. Any other ideas??

  21. I can’t wait to try this! I have a problem with flies at the back door that seem to wait in anticipation for the door to open so they can enter. Once inside, they don’t last long as I have two feral cats that stalk them till death, but I can’t stand them being in the house for even a few minutes. Of course, getting ahold of a 2 litter plastic bottle will be my first challenge. Maybe I’ll stalk the bottle return at the grocery store and give up a dime for one. Lol.

  22. I use a similar homemade trap to catch fruit flies in my house. I place a little apple cider vinegar (about 1/4 inch) in the bottom of a quart size canning jar, then place a few slices of banana into the vinegar. I make a funnel out of a piece of paper, and place it in the jar like the picture of the soda bottle in your post, and tape the funnel/jar opening together with masking tape. This works great for fruit flies!

    I wish I had know about the fly trap with potatoes about 4 years ago, when I got a horrible fly infestation in my house. I found the source, a recently purchased bag of potatoes with a rotten one inside. It was too late though, because the flies were already established somewhere in my basement. I fought them until we finally gutted the basement, threw just about everything away, and remodeled it. Luckily the remodel was already planned, and thankfully it solved the fly infestation as well.

    • We do the same thing with the apple cider vinegar but you don’t need to use bananas. We use straight vinegar and it works perfectly and is probably less messy without the bananas.

    • Hi Hi,
      We had heard of a few ways with the fruit flys and so my daughter and I wanted to see which way worked best. so we tried the apple cider and dish soap in a shallow cup and caught only a few but we also tried some sugar water and dish soap in a shallow cup and caught a ton !

    • Fruit flies are easy! I’m in Australia and I just strategically place little shot glasses of Apple cider vinegar around my fruit bowls and I add a tiny drop of dishwashing detergent to each glass. The detergent breaks up the surface tension of the vinegar, so they land and then drown. No cone or top needed! Awesome trap


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