Thursday, May 9, 2013

Homemade Fly Traps

A few years ago I lost my first sheep, my grand beautiful ram, to flystrike. At the time I didn't even know about flystrike. So I devastated and felt really guilty when he died. I let him down. I swore I'd make sure I'd never lose another sheep to flies.

Since then I'm careful to check on each individual sheep daily. And if we get a rain period where their fleece stays soaked, I will shear them down to 1/2 inch of fuzz. Anything longer tends to draw the flies. And if I still see flies landing on the sheep, then I drag out the hose and dog shampoo. Everyone (including myself) gets a bath! Happily that doesn't happen often.

Plus I started a war on carrion eating flies. They are the buggers that attack the sheep. I don't know what species of flies they are, but there are a couple of different kinds. I tried a few things in the beginning that weren't very effective. Fly bait (golden malrin), store bought fly traps using a commercial lure, fly paper. I soon realized that I wasn't catching scads flies and I seemed to be catching the wrong ones. Duh, I was using the wrong bait! I needed something that smelled dead or dying, or like rotting sheep fleece.

I couldn't help but notice that a dead animal, be it a rat, mongoose, bird or whatever, quickly drew my target flies. And if that animal was cut open (for example, the cat chewed on it), it really, really attracted flesh eating flies. So I concluded the dead meat would be a better bait. So I sacrificed a piece of raw chicken breast to the fly trapping experiment. Guess was a dud. So I next used a bit of beef steak. Another dud. Pork loin, yet another dud. What gives? I guess that commercial meat is too "clean" for the flies taste. So the next rat that the cats killed I wacked it up well with a machete and stuffed it into the fly trap. Success! The trap was crammed full of flies in one day.

soda bottle trap baited with meat and water
Ok, I had the bait problem solved. Now to make a homemade trap out of supplies on hand. The store bought trap worked just fine, but I wanted to go with homemade.
only one entrance hole which gets covered with a cap

Using two-liter soda bottles, I made lots of traps emulating the store trap design. They all worked but the wind tended to blow them over. I thought I might make something better. So I experimented.

My milk jug traps worked ok. But they were not as easy to empty and recharge with bait. Nor did they catch as many flies. So I wanted better.
old cheese bottle & milk jug cap

I tried clear plastic and glass jars. I tried holes in the lids, holes on the sides. They were very easy to empty and recharge, and stable so that the wind didn't blow them over. But they didn't catch as many flies as the soda bottles. 

So I went back to the soda bottles. I solved the blowing over problem by just anchoring them well between three rocks. They are very easy to enpty and recharge, Using a slotted spoon, I can harvest the dead flies and drop them into the  chicken food. And by far......real far......they are the best at catching lots of flies. 

milk jug with hole in the top
By using a piece of fresh dead animal as bait, does it stink? Sure, so I don't set up the trap near the house. Since I want to be protecting my sheep, the traps go out in the pastures. Besides, it's not houseflies that I'm dealing with. It's carrion type flies.

Whenever the cats bless me with another dead rat, I use it to refresh the traps. Of if I am given a piece of fresh killed meat ( pig, mouflon, whatever) I will set aside some for the fly traps.

Each of my fly traps catches at least a cupful of flies on a sunny day. Since I live in a farming area, the fly population never deminishes. But since coming up with my current fly trap design, I no longer see lots of flies in the pastures. I still keep a close eye on my sheep, especially when it rains for more than two days in arow, but so far things have been fine. The flies appear to prefer the stinky traps over the wet
sheep. Good!


  1. Another great post Su Ba, thank-you! I think i can find some stinky fish scraps that will make fine fly trap bait.
    Check out the Mac Daddy fly trap i found on google:
    Not that i need any more projects! I think your soda-pop traps will work just fine for me ; )

    1. Aloha, Julie!
      Nice find on the fly trap - the instructions sound hilarious, using basswood cut mil-spec with mitered joints, da kine, but a staple gun, sticks, some cheap aluminum screen, you still got time to catch the early evening news. I wonder why no one mentioned feeding the dead flies to chickens!?! Eh, I tried opening the Hawai`i Grazing Lands Conservation Initiative [man, they need a shorter handle!] link on your bloglist, but it won't work. You and Su Ba could meet up there and teach, I bet.

    2. Barry, I'm with you on not worrying about precision construction. I cobble things together for functionality, not beauty. I get flack for not being precise, detailed, and neat. Oh well. I just want to get the job done and move on. Running this farm essentially by myself, I have very little time to get everything done. Thus, no time to waste on mitered corners, glue and clamps, etc. So I wack it together and get to the next job. If people don't like it, they can come volunteer on my farm and do it better!

    3. Barry thanks for the heads up, i'll fix the link. Su Ba, i think, could teach. Me? I am an idiot ; ) But working on changing that!

      Fascinating follow-up Su Ba, and sorry for the comments hijack.

  2. Julie, believe it or not, I built a very similar fly trap back in 1979. My pony was plagued with flies which she hated. Spent much of her day kicking the air to rid herself of flies. So I kept her doused, literally drenched, in fly spray. But the flies were relentless. When she got toxic because of the fly spray, I knew I had to either do something about the flies or keep her forever in a screened stall. Since living in isolation is not much if life, I started studying the flies.

    For a couple of years I used 5 gallon buckets with golden malrin in the bottom. After 2-3 years I discovered, by thoughtless accident, that fresh dog poop atop the golden marlin caught 300% more flies. By then I had dozens of bucket traps that needed daily baiting and keeping away from the rain. Then disaster struck. My young cat discovered that the buckets were fun places to play with dying flies. He died from golden marlin poisoning. I was aghast, distraught.

    I worked on better, safer traps. Somewhere along the line of trying to make non-toxic fly traps I saw that flies tended to fly upwards towards the light. They'd crawl through dark places, but headed for the light. After many designs based on this concept, a fly trap such as the "Cadillac of all..." was born. The best bait for the flies that plagued my pony was fresh dog poop. So each morning I baited the traps-- I had four, one on each corner of the pony corral. I caught so many flies that I had to make a little trapdoor in the side so that I could vacuum out the dead flies because the 2'x2'x2' trap box literally would get full in a couple weeks. Coco's life was better after that and I only needed touse fly spray on her legs.

    I had a friend who worked for the NJ forestry department. He saw my fly traps and must have passed the information along to his fellow employees, because a few years later the state was using super giant versions of this trap to trap marsh flies. They improved on my design in order to get greenhead flies. Now I see that there are lots of variations of the original idea.

    I tried using my old fly box idea on the carrion flies, but it didn't work so well. The main problem was that my cats and dogs would pester the traps, playing with the flies. That's why I tried other things. I find that the soda bottle traps catch the most carrion flies, and besides, they are easier to use and hang out of the reach of the cats. But I do have one of my box traps beside the dog pen (I have to pen up all but two of my dogs at night because otherwise they bark). It catches the dog manure flies just great! And I don't mind so much if the cats pester the trap, interfering with the flies.

    Now if I could only come up with some better mosquito ideas. Some rainy day I'll work on it!

  3. Great post! I found this:
    to maybe help you to locally decrease the mosquito population in your immediate area temporarily. ("Ya cain't win, ya know")
    The retail version looks way too spendy, but the craft level of the second one is more my skill level. One of the commenters suggested two fans, in a push/pull setup, to direct those skeeters into the trap while keeping you cool. Akamai!