Self-made horsefly trap design goes viral

Dan Owsley from Salem, Indiana built a horsefly trap a few days ago. Horseflies can be a big problem when keeping horses; thus the name,” Horsefly.” They can also bite humans.

On day 1, his horsefly trap killed 146 flies. On day 2, it killed killed 375! Owsley thought, “We either have a terrible horsefly problem or it’s a great trap!” 

Owsley’s 7-day total was 1,697 horseflies killed. He said, “They are big (about 1″ long) and easy to count. The dead flies need to be cleaned out every day so they won’t rot, so it’s a good time to take a count if you want to.”

How It Works: Horseflies are visual hunters. From a distance, the black bag looks like something to bite, so the horseflies do a flyover and are deflected into the soapy water, and drown within a few seconds.

How to Make Your Own: “The leg configuration can be whatever you like. I just made mine so it would be easy to move and change the bag. Also, the plexiglass needs to be kept clean and free of scratches. We have high humidity where I live, so I squeegee the dew off the plexiglass every morning. The saw cuts in the 2×4 that holds the plexiglass are at 45 degree angles, about an inch deep. The plexiglass fits tightly enough that I didn’t need to fasten it in any way. The bag I used was a 55-gallon trash bag from Sam’s Club. It holds about a 5-gallon bucket of water with a big squirt of liquid dish soap.

“Make sure to set your trap in an open area where the horseflies can see it from a distance. You may need to move it around until you find the “sweet spot.” Clean it out with a cat litter scoop or large slotted spoon. 

“Be sure to paint the top board a dark color so the light color of the wood won’t reflect in the plexiglass and make it visible to the flies,” Owsley explained.

The video below is from Dan Fowler in Tennessee of his horsefly trap set-up. He caught over 6,300 in one week!

For more information, visit Dan’s original Facebook post at


Owsley’s original rig:


Comments are closed.