how to get rid of horse flies

Introduction

Horse flies are more than just an annoyance. Their painful bites can stress horses, reduce weight gain and milk production, and even transmit disease. If you keep horses, cattle, or other livestock, controlling horse flies is essential for animal welfare and your own comfort.

This guide explains why horse flies show up, then walks through proven control methods, natural remedies, and practical prevention tips. The focus is on realistic, actionable steps you can use around a typical farm, yard, or stable.

Why Flies Appear

Understanding why horse flies are drawn to your property helps you target them more effectively.

1. Ideal breeding sites

Horse flies (family Tabanidae) lay eggs in moist or wet areas. Common breeding sites include:

• Marshy ground and wetlands
• Ponds, ditches, and slow streams with vegetation
• Waterlogged fields and low-lying areas after rain
• Manure and muck heaps that stay damp

Larvae develop in wet soil or water. If your property has standing water or poorly drained spots, you’re providing horse flies with prime habitat.

2. Presence of animals and humans

Female horse flies need blood to produce eggs. They are attracted to:

• Horses, cattle, sheep, and other livestock
• Humans, especially when working outdoors
• Pets can be bitten as well

These insects use sight and smell to locate hosts: movement, body heat, dark colors, and exhaled CO₂ draw them in.

3. Weather and season

Horse flies are seasonal and weather-dependent:

• Peak activity: late spring through summer, often into early fall
• Most active on hot, sunny, still days
• Less active in strong wind, heavy rain, or cool temperatures

4. Visual and scent cues

Horse flies are strongly attracted to:

• Dark, moving objects (like a horse’s body)
• Shiny surfaces and reflections on water
• Body odors and sweat

Anything that mimics a large animal—movement plus dark color—can pull them in.

5 Proven Methods to Get Rid of Horse Flies

You won’t completely eliminate horse flies, but you can drastically reduce their numbers and protect your animals. The best results come from combining several methods.

1. Use specialized horse fly traps

Mechanical traps are one of the most effective tools against horse flies.

Commercial traps

• H-traps / Horse Pal / Eliminator traps: Use a black ball or cone under a hood. When flies try to bite the “animal”, they fly upward and get trapped.
• Recommended placement:
  • In sunny, open areas where flies patrol
  • 10–20 meters (30–60 ft) from stables or outdoor seating, not right next to animals
  • 1–1.5 m (3–5 ft) above the ground
• Maintenance:
  • Empty traps regularly, especially in peak season
  • Clean and repair nets/containers as needed

DIY ball trap

To build a simple DIY horse fly trap:

1. Get a large black ball (e.g., exercise ball or painted balloon).
2. Hang it under a funnel or cone made from plastic or a stiff fabric.
3. Fix a clear collection container (e.g., jar or plastic bottle) on top of the funnel.
4. Mount the setup on a frame so the ball hangs about 1 m (3 ft) above the ground and can move in the breeze.

Horse flies land to bite the ball, then fly upward into the funnel and get trapped in the container.

2. Protect horses with physical barriers

Physical protection is essential during high fly pressure.

• Fly sheets and masks:
  • Use lightweight, breathable fly sheets that cover the body, chest, and belly when possible.
  • Fly masks protect eyes, ears, and faces; choose models with good visibility and secure closures.
• Leg protection:
  • Fly boots or wraps can protect lower legs, a common target for horse flies.
• Stabling at peak times:
  • Keep horses indoors during the hottest, sunniest hours when flies are most active.
  • Use fans in stalls; constant airflow makes it harder for flies to land.

3. Apply effective repellents and insecticides

Chemical and natural repellents can reduce bites, though they need reapplication.

On-animal sprays and wipes

• Horse-specific fly sprays:
  • Look for EPA-registered products labeled for horse flies.
  • Follow label directions exactly, including reapplication intervals.
• Application tips:
  • Apply in a well-ventilated area.
  • Avoid eyes, nostrils, and mucous membranes.
  • Test a small area first to check for skin sensitivity.

Environmental sprays (use with care)

• Residual insecticides (e.g., permethrin-based) can be used on:
  • Barn walls and ceilings
  • Door frames and resting areas where flies land
• Do not spray directly into water or on pasture where animals graze, unless product labeling specifically allows it.
• Always wear protective gear and follow safety instructions on the label.

4. Reduce breeding sites and habitat

Habitat management cuts down future fly populations.

• Improve drainage:
  • Fill in low-lying puddle-prone areas with soil or gravel.
  • Install drainage ditches or French drains in chronically wet spots.
  • Divert roof runoff away from paddocks and stables.
• Manage water bodies:
  • Keep banks of ponds and ditches trimmed so water can dry faster.
  • Remove old tires, troughs, and containers that hold stagnant water.
• Manure management:
  • Clean stalls and paddocks daily.
  • Store manure on a well-drained pad, ideally covered, away from barns.
  • Turn compost regularly to speed drying and breakdown.

5. Strategic pasture and turnout management

You can reduce exposure by adjusting how and when horses are outside.

• Turnout timing:
  • Shift turnout to early morning, evening, or overnight when horse flies are less active.
  • Avoid mid-day turnout on hot, sunny days during peak season.
• Use natural wind:
  • Turn horses out in higher, breezy fields—horse flies dislike strong wind.
  • Place shelters or loafing sheds where there is cross-breeze.
• Water placement:
  • Keep water troughs away from marshy areas and ditch edges.
  • Regularly scrub troughs to avoid algae and organic buildup.

Natural Remedies for Horse Flies

If you want lower-chemical or complementary approaches, these natural methods can help. They work best combined with traps and habitat management.

1. Essential oil blends (for horses, not people only)

Certain essential oils can deter horse flies when properly diluted:

• Commonly used oils: citronella, eucalyptus, lemongrass, geranium, lavender, tea tree (use with caution), and cedarwood.
• Application guidelines:
  • Always dilute essential oils in a carrier (e.g., water with a small amount of mild soap, or commercial fly spray base).
  • Never apply undiluted oils directly to a horse’s skin.
  • Avoid eyes, nose, mouth, and any irritated skin.

Natural sprays typically need more frequent reapplication (every few hours) than synthetic repellents.

2. Homemade vinegar spray

A simple homemade spray can help for light fly pressure:

• Basic recipe:
  • 2 cups apple cider vinegar
  • 1 cup water
  • 1–2 tablespoons of mild dish soap (helps it stick)
  • Optional: 10–20 drops of essential oils like eucalyptus or citronella
• Use:
  • Shake well before each use.
  • Spray lightly on the horse’s body, avoiding sensitive areas.
  • Test on a small area first to ensure no skin irritation.

3. Fans and air movement

Horse flies prefer still air. Strong airflow makes it harder for them to land.

• Install box fans or ceiling fans in stalls and barn aisles.
• Position horses in breezy spots when tied or groomed outdoors.
• Ensure cords and fans are safely installed, protected, and out of chewing reach.

4. Beneficial predators and biodiversity

Encouraging natural predators won’t eliminate horse flies, but it can help keep overall biting fly populations lower.

• Birds: Swallows, martins, and other insect-eating birds consume large numbers of flying insects. Nesting boxes and perches can attract them.
• Predatory insects: Dragonflies and certain beetles prey on fly larvae and adults.
• Avoid broad-spectrum insecticides that kill these allies along with pests.

Prevention Tips: Keeping Horse Flies Away Long-Term

Long-term control relies on consistent, preventive management rather than one-time fixes.

1. Maintain strict cleanliness

• Remove manure from stalls and paddocks daily.
• Clean feed areas, spilled grain, and wet bedding promptly.
• Keep garbage cans covered and away from barns.

2. Manage water effectively

• Fix leaky faucets and automatic waterers.
• Eliminate unnecessary standing water (buckets, troughs, old tanks, tires).
• Grade or fill low spots where water pools after rain.

3. Install physical barriers on buildings

• Use fine-mesh screens on windows and vents in barns.
• Install self-closing doors on stable entrances where practical.
• Hang plastic strip curtains on barn doorways used frequently; these allow airflow while blocking many flies.

4. Rotate and rest pastures

• Rotate horses between fields to avoid overgrazing and muddy patches.
• Allow overused pastures to rest and dry out.
• Keep grazing areas as dry and well-drained as possible.

5. Combine methods into a seasonal plan

For the best results, create a simple seasonal management plan:

• Early spring:
  • Fix drainage issues and remove standing water.
  • Set up traps before fly numbers surge.
• Late spring–summer:
  • Use fly sheets, masks, and boots.
  • Apply repellents and maintain traps weekly.
  • Adjust turnout times to avoid peak fly activity.
• Fall:
  • Continue manure and water management.
  • Inspect and repair traps and barn screens for next season.

FAQ

What attracts horse flies the most?

Horse flies are attracted to large, dark, moving objects (like horses), body heat, sweat, exhaled CO₂, and moist environments. They are especially active on hot, sunny days near water and wetlands.

Do horse flies bite humans?

Yes. Female horse flies bite humans as well as animals. Their mouthparts cut the skin, causing painful bites that can swell and itch.

Can horse flies transmit diseases?

Horse flies can mechanically transmit certain pathogens between animals, including some blood-borne diseases. They can also cause secondary infections at bite sites if the skin is damaged and not kept clean. If you notice signs of infection or illness in a horse after heavy fly exposure, consult a veterinarian.

What is the most effective way to get rid of horse flies?

No single method works alone. The most effective approach is a combination of:

• Good-quality horse fly traps
• Physical protection (fly sheets, masks, stabling during peak hours)
• Repellents for short-term relief
• Habitat management to reduce breeding sites

Do regular fly traps work on horse flies?

Sticky strips and typical housefly traps are usually not very effective on horse flies. They prefer larger, moving targets. Use traps specifically designed for horse flies that mimic animal hosts and direct flies into a collection chamber.

Are essential oils safe for horses?

Some essential oils can be used safely when properly diluted, but horses can be sensitive. Always:

• Test on a small area first.
• Avoid eyes, nose, and broken skin.
• Stop using if irritation occurs.

If in doubt, consult your vet before using essential oils on horses, especially pregnant or sensitive animals.

How often should I apply fly spray?

Follow the instructions on the product label. Many sprays provide protection for a few hours to a day. Sweat, rain, and bathing will shorten the protection time, so you may need to reapply more frequently during heavy work or hot weather.

Can I completely eliminate horse flies?

In most rural and semi-rural areas, complete elimination is unrealistic because horse flies can travel long distances from surrounding wetlands. However, with traps, protection, and good management, you can greatly reduce their numbers and minimize the impact on your horses and family.

When is horse fly season?

Horse fly season varies by region but typically runs from late spring through the summer and into early fall. Activity peaks on warm, sunny, humid days.

Are horse fly bites dangerous for horses?

Beyond pain and irritation, heavy biting can cause:

• Stress and reduced performance
• Blood loss in extreme infestations
• Skin damage, leading to infections

Protective measures and prompt treatment of any irritated or open areas can reduce health risks.