6 Best DIY Horse Fly Traps For Budget Conscious Farmers That Actually Work
Protect your livestock without overspending. This guide details 6 proven, easy-to-build DIY horse fly traps for the budget-conscious farmer.
That relentless buzzing sound followed by a painful welt on your horse is a familiar, frustrating part of summer on the farm. You see your animals stomping, swishing, and running from an enemy they can’t shake. Controlling these biting pests isn’t just about comfort; it’s about preventing stress, weight loss, and potential disease transmission without breaking the bank on commercial solutions.
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Understanding Horse Fly Behavior on the Farm
To beat the horse fly, you have to think like one. Unlike house flies or stable flies that are drawn to manure and sweet smells, horse flies are visual hunters. They are attracted to large, dark, moving objects that look like a potential blood meal—your horse, your cattle, or even you.
They patrol sunny areas, fencelines, and the edges of woods, waiting to ambush a target. They use their enormous eyes to spot movement from a distance. Once they land, they don’t mess around; the females deliver a nasty, scissor-like bite to draw blood for their eggs. This is the key weakness we exploit with DIY traps: their reliance on sight over smell.
Understanding this distinction is crucial. A smelly bait trap that works wonders on house flies in the barn will do absolutely nothing for the horse flies dive-bombing your animals in the pasture. Our traps need to mimic a large, dark animal to draw them in. Movement, even just the gentle sway of a trap in the wind, significantly increases its effectiveness.
The Tangle-Trap Coated Milk Jug: A Simple Sticky Trap
This is the fastest and cheapest way to start catching horse flies today. All you need is an empty plastic milk jug, some black spray paint, a string, and a can of Tangle-Trap or a similar super-sticky coating. The concept is brutally simple: create a dark, enticing target and make it impossible for the flies to leave once they land.
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First, paint the milk jug black to create that dark silhouette horse flies can’t resist. Once it’s dry, hang it from a tree branch or a post along a fenceline where you see flies congregating. Hang it at about the height of your horse’s back, allowing it to swing freely in the breeze. The movement is a critical attractant.
The final step is to coat the jug with your sticky substance. Be warned, this stuff is incredibly messy, so wear gloves. The flies see the dark, moving jug, land to investigate, and become permanently stuck. The main tradeoff here is maintenance; the jug will eventually become covered in flies and dust, requiring a messy recoating or replacement. But for a near-zero cost, its effectiveness is hard to beat.
The 5-Gallon Bucket Trap: A Classic DIY Design
The 5-gallon bucket trap is a classic for a reason—it’s sturdy, effective, and uses a non-sticky method to capture flies. This design relies on the fly’s natural behavior after it lands on a target. It consists of two main parts: a black bucket suspended upside down and a basin of soapy water directly beneath it.
To build it, you’ll mount a 5-gallon bucket, painted black, upside down on top of a T-post or wooden stake. The bucket acts as the visual lure. Underneath the bucket, you place a pan or basin filled with water and a few drops of dish soap. The soap is essential; it breaks the water’s surface tension, so when a fly falls in, it sinks immediately instead of just floating on top.
Here’s how it works: The horse fly is attracted to the large, dark bucket. It flies around it, bumps into it, and its natural instinct is often to drop straight down. It falls directly into the soapy water below and drowns. This trap is less messy than sticky traps and can hold a huge number of flies before needing to be emptied. Its only real downside is ensuring the water basin doesn’t dry out on hot days.
The Black Beach Ball Trap for Open Pastures
For large, open pastures where posts are inconvenient, the black beach ball trap is an ingenious solution. It uses the same principles of a dark, moving lure but in a portable and highly visible format. This trap mimics the rounded body of an animal and adds an upward-funneling capture mechanism.
You start with a large, black beach ball. You’ll need to build a simple tripod frame from wood or use a low-hanging tree branch to suspend the ball so it can swing freely. The movement is key. Above the ball, you construct a cone, typically from window screening or fine mesh, that funnels upward into a collection bottle or chamber at the top.
Flies are drawn to the dark, moving ball. They land, probe it, and, finding no blood, their instinct is to fly upwards towards the light. They fly up into the mesh cone, continue moving towards the light at the top, and end up trapped in the collection bottle. This design is incredibly effective and can be moved around the pasture to target different fly hotspots. It’s more of a project to build but offers outstanding, low-maintenance results.
The Yeast & Sugar Bottle Trap for Stable Flies
It’s critical to know your enemy. While the previous traps target visual-hunting horse flies, this trap is designed for stable flies and house flies, which are attracted to scent. If you have flies pestering your animals inside the barn or near manure piles, this is the trap you need.
The setup is a simple 2-liter soda bottle. You cut the top third off, invert it to create a funnel, and place it back into the bottom part of the bottle. The bait inside is what does the work. A common recipe is:
- A cup of warm water
- A quarter-cup of sugar
- A teaspoon of active dry yeast
The yeast consumes the sugar and releases a steady stream of carbon dioxide and fermentation odors, which are irresistible to stable and house flies. They fly down the funnel to get to the bait but can’t figure out how to fly back out. This trap costs pennies to make and is perfect for hanging around the barn, run-in shed, or near your compost area. Just don’t expect it to catch horse flies out in the pasture.
The T-Post and Black Plastic Sticky Trap
When you need to scale up your trapping efforts along a long fenceline or pasture edge, this method provides a massive trapping surface area. It’s a larger, more industrial version of the milk jug trap. It uses common farm materials: a T-post, a roll of black plastic sheeting, and a bucket of brush-on sticky coating.
Simply drive a T-post into the ground in a known fly path. Wrap a 3-4 foot section of the post with black plastic sheeting, securing it tightly with zip ties or wire. Then, using a disposable paintbrush, coat the entire plastic surface with your sticky adhesive. You’ve just created a huge, dark, stationary target that is lethal to any horse fly that lands on it.
The main advantage is its sheer size and simplicity. You can set up a dozen of these along a tree line in an afternoon. The primary tradeoff, like all sticky traps, is the mess and the non-selective nature of the trap. You may occasionally catch beneficial insects or, if placed poorly, even a small bird. For this reason, it’s best used in open areas away from dense brush where birds are more likely to perch.
Building a Walk-Through Manitoba Fly Trap
This is the ultimate DIY fly control solution, but it’s a significant construction project. A Manitoba-style walk-through trap is a passive system that removes flies from your animals every time they pass through it. It’s designed to be placed in a high-traffic gateway, like the entrance to the barn or a path to the water trough.
The trap is essentially a dark, narrow chute or tunnel that the horses walk through. The sides of the tunnel are lined with strips of burlap or cloth that brush against the horse’s sides and belly, dislodging flies. As the flies are knocked off, they instinctively fly towards the only light source available—an upward-facing V-shaped mesh chamber built into the roof of the tunnel.
Once inside the mesh chamber, the flies are trapped. They continue to fly towards the light at the top but cannot find their way back down into the dark tunnel. This design is brilliant because it works with your animals’ daily routines to provide constant, chemical-free fly removal. While it requires a significant upfront investment of time and materials, a well-built walk-through trap can dramatically reduce the fly population on your entire farm for years to come.
Placement and Bait Tips for Maximum Effectiveness
Where you put your trap is just as important as how you build it. A perfect trap in the wrong spot will catch nothing. Placement is everything. Since horse flies are visual hunters, their traps need to be out in the sun where they can be seen from a distance.
Position your visual traps (bucket, ball, jug, T-post) along the edges of pastures, near gates, and along paths where you see flies congregating. Don’t hide them in the shade; sunlight makes the dark silhouette stand out and also warms the trap, which seems to increase its appeal. Ensure they can move with the wind, as movement is a primary attractant.
For scent-based traps targeting stable and house flies, the opposite is true. Place them near the source of the problem: the barn entrance, near the manure pile, or by feed storage areas. For horse fly traps, forget complex baits. The "bait" is the trap itself—the dark color and movement. The only "enhancement" you might consider is a commercial octenol lure, a chemical that mimics animal breath, but the physical properties of the trap do 90% of the work.
There’s no single magic bullet for fly control, but a combination of these cheap, effective DIY traps can make a huge difference in your animals’ comfort and your own sanity. By understanding the specific behavior of the flies you’re targeting, you can build and place the right trap for the right job. Start with one or two simple designs, see what works best on your property, and reclaim your pasture from these summer pests.
