The Best Homemade Fly Trap for Outdoor

Learn how to DIY a fly trap that actually works using a mason jar (a soda bottle works too) and bait. These results are 100% real from my own backyard using household items and a stinky bait.

Homemade fly trap made out of a mason jar and a construction paper cone hangs on a brick wall.

This fly trap DIY works so well outside for green bottle flies, aka blowflies, that it’ll turn your stomach. How’s that for an endorsement? But more than the trap, the most important thing about this DIY – is the fly trap bait.

Living in an almost 200 year old house with backyard chickens means I’ve learned how to control a lot of pests.

The best time to control pests is BEFORE you see pests.

Catching flies is a whole lot easier if you start baiting before they start mating.

Get your fly trap made and placed outside a couple of days before warm weather arrives to keep the population under control from day 1.


Getting rid of fruit flies is a reader favourite.

Mouse in the house? How to get rid of mice.

Controlling flies with natural predators like parasitic wasps.


So when one of my chickens became sick with flystrike, a deadly affliction caused by bottle flies, I knew I had to head into battle against them.

I made and compared a few homemade fly traps including:

  1. a mason jar with paper cone
  2. a soda bottle with the top cut off and inverted
  3. good old fashioned fly strips (not DIY but I had to test them out!)

The results showed the trap wasn’t so much the determining factor in how well a homemade trap worked – it was the bait.

Mason Jar & Paper Cone Trap

Baited with raw shrimp.

Homemade fly trap hanging on red brick wall filled with flies because the right bait was used.

SUPPLIES

  • Mason jar
  • Standard sized sheet of paper
  • 1 raw shrimp
  • water

INSTRUCTIONS

  1. Roll a piece of paper or cardstock into a cone and tape it together.
  2. Put the cone into a mason jar of any size, making sure there’s room at the bottom of the jar for at least 2″ of water. You may need to adjust the shape of your cone.
  3. Add water and a single raw shrimp to the jar.
  4. Wait.  Within a couple of days your jar will be FULL of flies.

Yep. A raw shrimp allowed to rot in the sun for days until it has the putrid smell of liquid internal organs.  That was the key to a successful fly trap.

DIY mason jar fly trap filled with flies.

Soda Pop Bottle Fly Trap

Baited with commercial, store bought fly bait.

Homemade fly trap hanging on red exterior brick wall showing no flies in it.

This is the basic DIY fly catcher you see all over Pinterest.

SUPPLIES

  • Plastic soda bottle
  • Scissors
  • Commercial fly bait

INSTRUCTIONS

  1. Cut the top off of the plastic pop or water bottle.
  2. Flip the top upside down (it’ll look like a funnel) and stick it back into the bottle.
  3. Pour a couple of inches of water into the bottom of the trap and then bait it.

In this experiment I used I used store bought fly bait.  The container is a 2 litre pop bottle.  The flies can get into the bottle, but can’t figure out how to get out.  Then they drown.

This trap caught NO flies.  Not a single one.

But it isn’t the design of the trap that was flawed, it was the bait. Store bought fly bait attracted no flies at all. 

Fly bait is the most important part of your fly traps.


Fly Strips

The fly strip cost a couple of dollars and dangled sadly from my window frame enticing no flies at all, just hanging there like a limp tongue.

I wanted to make sure I gave all the fly traps a good shot so I kept them all out for a week.  This is how things had progressed after 4 days.


Fly Trap Results

Mason Jar with natural fly bait (shrimp) – Caught HUNDREDS of flies in 4 days

Soda bottle with commercial fly bait – Caught ZERO flies in 4 days

Fly strip – Caught 7 flies in 4 days

After 4 days it was pretty clear that the rotting shrimp was the only way to go in terms of bait.

My homemade fly trap recommendations

The trap

Either the mason jar or soda bottle method will work very well to catch flies outdoors.

The bait

Raw shrimp is your BEST choice for fly trap bait.


For this experiment I only baited the soda bottle with commercial bait (which caught nothing) but since then I’ve tried it successfully with shrimp as a bait. It works just as well as the mason jar with paper cone.

Testing Different Baits

I experimented with different baits including:

  • Fermented chicken feed
  • Raw sweet corn 
  • Fresh chicken poop*
  • Raw shrimp*

* If you use meat, seafood or poop understand that this gives the flies a place to lay their eggs. That means if you use any of these things that after several days you will ALSO have maggots appear in your fly trap. Consider this when choosing your bait.

The rotting shrimp was the winner by a shrimpboat load.

The only issue with the enticing smell of rotting shrimp was the vile smell of rotting shrimp.  If you place your container up high enough (above nose level) you miss most of the stench but given any kind of downward breeze you suddenly feel like you’re walking through a rotting whale carcass.

By day 7 I was pretty sure I would have to try something else because I couldn’t stand the stench of the shrimp no matter how well it worked.  Then a funny thing happened.  By days 8 and 9 the trap was so filled with flies they actually suffocated the smell of the shrimp.  Yet somehow the stink was enough to continue to attract the flies.

By day 14 the mason jar trap was almost completely FULL of flies.

The huge success of a mason jar as a fly trap shown as it hangs on a red brick wall filled with flies.

Home Fly Trap on Day 14

Because there were so many flies I couldn’t smell the shrimp at all and the jar was almost full.

After 20 days it stunk again. Stunk like the guts of a hot monkey. But the stink could have been the mass grave of flies as well.

Mason jar fly trap hanging on exterior red brick wall, filled with flies after 14 days.

To save myself some grief and whatever happens to be in my stomach, when it comes time to remove the jar I just  tie a plastic bag around my head, put a lid on the jar and throw the whole thing in the garbage.

Just kidding. I don’t tie a bag on my head. I’m an excellent breath holder on account of my cat’s horrific gut issues when she – coincidentally – eats seafood.

Fly trap placement

The best place to put fly traps is actually AWAY from where your fly problem is.  (The dog run/chicken coop/picnic area.) The point is to draw the flies way from wherever it is they’re fond of.

What is the best home remedy to get rid of flies?

The best way to get rid of flies around your house is to use TWO methods.

  • Parasitic wasps (really just tiny little flying things that are in no way as menacing as their name alludes to) will kill most flies before they even become flies. The wasps kill them in the larvae stage.

AND

How Do I Get Rid of Flies Inside?

Well, I’ll tell you … a bottle filled with stinking, rotting seafood probably isn’t the best way. But if you fill a bottle with some non stinking fly bait like the liquid recipe below, it won’t be quite as offensive.

This recipe won’t work nearly as well as rotting flesh but it will work to catch flies.

Fly Bait Recipe

  • 1/2 cup water
  • 1/2 cup vinegar
  • 2 Tbsps sugar
  • 1 Tbsp dish soap (the dish soap breaks the surface tension of the water and vinegar, making the flies unable to use it as a launching pad when they fall in it)

Use either the mason jar or plastic bottle method. You can use a small water bottle instead of a large soda bottle.

Now that you’ve mostly eliminated one insect from your yard (totally understandable, flies are sex crazed monsters that feed on crap and then land on your corn on the cob), you might want to help out another.

Learn how to raise monarch butterflies on you property, something I’ve been doing for over a decade.

If you have a great fly bait recipe, leave it in the comments below. If you have a great maggot story maybe just keep that to yourself.  Just kidding. Obviously, I’d love to hear the maggot stories.


 

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The Best Homemade Fly Trap for Outdoor

257 Comments

  1. Gwen says:

    I’m going to try your method, as it sounds really workable.

    My father, the child of homesteaders, told us how they dealt with flies on the farm.
    They would find one of those huge poisonous toadstools. They would put it upside down, and pour sugar water in the inverted cone of the mushroom. The sugar attracted the flies, the poison from the mushroom killed them.

    I’ve never tried this method. Despite living in the tropics, I rarely see mushrooms. And previously, I’d lived in cities, so usually flies weren’t much of an issue.

  2. Darlene Meyers says:

    Hi Karen

    Long time lover of your blog. Are you not writing any new posts? For a couple of years now you have reused the postings you wrote long ago. I guess I started around “The Fella” I am really confused…

    • Karen says:

      HI Darlene. I write both new and update old posts. :) Nothing to be confused about. It takes about 3 days to write or rewrite a post now because the world of Google has changed and I have to make my posts more attractive to the almighty Google. Also I started writing these posts 12 years ago and with many of the DIYS I’ve acquired new and better ways to do a lot of things. ~ karen!

  3. Becky says:

    Using the inverted bottle, I pour a sprinkle of yeast in, top with some sugar, a bit of water, stick that sucker in the sun and it’s full of flies in an instant. So gross but weirdly satisfying.

  4. Suzy says:

    Would this work for wasps? We have a big problem every year and we can’t find where the nest is.

  5. Frances Akis says:

    I have a hard headed husband who did not follow your suggestions. And for days caught NOTHING. I told him what you said to do several times while he complained….finally he listened but what we thought was a few raw shrimp for fishing turned out to be pieces of liver…so not having any shrimp we decided to try. He likes to use a huge bottle so I told him I guess it would work but he must seal around the cut area (this is a plastic oil bottle). Because it is not the shrimp that would give the rotted smell…he wanted to add some yeast and sugar to speed up the rotting of the liver….we will see! He has two bottles in the garden area like a race to see what happens. I hope your idea works better as I know these traps work if you put the right bait in it. I will reply when we see flies entering the new bottle as the first one has NOTHING after four days.

    • Karen says:

      Lemme know Frances! Although I can’t guarantee it’ll work without the shrimp. They really are magic. I’ve tried almost all baits and bait ideas. It usually takes a couple of days for the shrimp to become revolting enough to attract flies. ~ karen!

      • Melissa says:

        Hmmmm….I wonder how fish sauce would work, given that’s its basically pre-rotted shrimp…

  6. Dennis says:

    Does anyone have a solution to either keep no see ums away from an area or to lure and trap them where one has to work like in a garden? I’ve never experienced them before in the past and paid no attention until the next day when my arms broke out in big welts that were extra itchy and lasted for days. Tried coating all exposed parts in deet after that but if I missed a square inch somewhere these little buggers found it pretty quick and took advantage of my sloppy application.

  7. Extremely helpful! I’ll do IT.

  8. Amy says:

    Okay, this was fascinating. I also learn a lot from scanning the comments. But here’s something that I am struggling with: BITING flies. They are not the Blue bottle flies, but are the nasty little buggars that will cluster on my arms, legs, back and face and will BITE. And the bites are so painful! They are not attracted to baits that smell like rotting flesh. I’ve got a hoophouse that I grow veggies in for fun and profit, and some days I can’t even work in there because of the BITING. I have hung fly strips near where I need to work that day, and it does seem to distract a few of them, but —-can anybody help? I’ve consulted Google and Pinterest, but you know . . they lie. So.

    • Karen says:

      Like deerfly you mean? They hurt when they bite! And they’re big. The only thing I’d say that should work are the fly strips. I used one once that was GREAT but I can’t remember what was great about it, lol. It was much wider than a regular small fly strip, I can remember that. It may have had stripes on it? ~ karen!

  9. Marty says:

    How’ bout a mouse? I use discarded narrow necked bottles, ie vinegar, wine, etc, cheap soda and a drop of dish soap. Attacks everything, not in ever bottle, but recently a mouse! Now that stunk to high Heaven after a a while. I just thought it was the rotting wasps, flies, moths, ants, earwigs…I’ve never “trapped” a mouse in a bottle before! I’ve got some bottles hangin still baiting, that’ll make you barf, but hey, if they keep on catching all the wasps, and flies, my hummingbirds will be able to feed in peace! I will try your formal new time tho, I never thought of using vinegar.

  10. Leslie Russell says:

    Ok. So I know this is an older post but it caught my eye again. In one of the replies you said you hung one of the traps in your coop. Do you leave it in there? All smelly? Or do you take it out when they go to bed? I’m wondering if I wouldn’t actually be calling more flies to the area. I do have a problem with those horrible green flies and it’s a real problem for my chickens. It scares me.

  11. Jerry Lincoln says:

    When I was a little boy my Dad told me that my Mom was an Artist because she drew flies!

  12. Diana Robinson says:

    30 years of living in dairy farm country in Eastern Ontario have taught me much about flies. The most effective way to control them in the house is with the clear window fly control traps, so named by the manufacturer. They are clear strips with adhesive that catch
    anything that lands on them. The brand I buy are made in Sweden, I just noticed. You can get them at your farm supply store. Put them in the lower and upper corners of the windows – all the windows! and over time the problem resolves. They can’t lay eggs because they are caught by the adhesive very fast, where they die. They get a bit gross looking when covered with dead insects but they work. Now, can anyone help with earwigs, which have eaten everything I planted this year! I’ve tried everything I think, but am open to new ways to murder the little buggers.

    • Janice says:

      Take an empty sardine or cat food can and add a shallow layer of cooking oil. Place the can in a dark area like behind a potted plant. Earwigs crawl in and drown. I have caught hundreds this way! Simply throw the whole thing away when full.

  13. Dan says:

    We don’t have a problem with flies, or at least I didn’t think so. I made the mistake of dumping some garbage containing chicken bones and maybe some old hot dogs directly into our curbside bin (kept in the garage until pickup day). I opened it a few days later to throw some trash in, and the sides and inside lid were covered with thousands of maggots. Yuk! The next day the maggots were on the garage floor – double yuk! I moved the bin outside until pickup day (weekly), then washed it out after it was emptied.

    I won’t make the mistake of dumping unwrapped garbage into our bin again (though it bugs me to wrap my trash in plastic just so it can be stored cleanly at the landfill), but what I really wondered was where all the maggots came from. I guess normally we just eat them in our food before we can see them :0

    • Misty says:

      Dan, no we don’t eat them before they are big enough to see.. gross.. you definitely have flies around there bc that’s how maggots are made. Somehow, flies got into your trash and laid eggs in it hence where the maggots come into play. Next time, maybe try pouring a cap full of bleach over your trash. It helps keep them away in mine anyways..

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