Fly Control for Horses: The Ultimate Guide for Equestrians

The life cycle of flies consists of three stages: eggs, larvae/pupae, and adult flies. Female flies lay their eggs on organic matter like your horse's manure. These eggs hatch into larvae, which are also known as maggots. The larvae feed on the manure and grow rapidly, eventually morphing into pupae. The pupal stage is a transitional phase where the fly undergoes metamorphosis to transform into an adult fly. The adult fly then begins the life cycle all over again!

Flies and Mosquitoes of Horses, by Charles M. Hendrix, DVM, PhD. Now that we better understand the fly life cycle, let us take a look at control approaches that specifically target each stage.

Horse Fly Eggs

The prevention of fly eggs relies heavily on a consistent cleaning schedule, as previously discussed. By removing manure and bedding at least daily, flies will have fewer opportunities to lay their eggs in the barn. Overall, the less manure on your property, the fewer flies you will have.

Another method to eliminate fly eggs is by feeding an insect control supplement. Feed-throughs are fed directly to your horse to prevent fly eggs from hatching in their manure. Some feed-through supplements can even work against the larvae stage to prevent fly growth. They break the fly cycle by not allowing the larvae to develop their exoskeletons needed for maturity.

It should be noted that in order for feed-through supplements to truly be successful, the entire barn should be on the same program or regimen. If only one horse is on such a supplement, flies will still have plenty of opportunities in the next stall.

Larvae & Pupae

Introducing fly predators to your barn can help prevent larvae and pupae from ever reaching the adult stage. Fly predators are gnat-sized bugs that are natural enemies to many types of flies; they lay eggs inside the fly pupa, which destroys the flies at the pupal stage in return.

Fly predators can be placed in a manure pile, along the fence line of a pasture, or in any moist environment where flies like to breed. With maintenance, fly predators can work all season long to naturally prevent flies from bothering you and your horse during the summer season.

Adult Horse Flies

There are a wide variety of ways for equestrians to combat adult flies, including but not limited to: fly sprays, fly traps, and property equipment. Continue reading to learn the advantages of each preventative method.

Below is a map of the United States on when fly season generally occurs throughout the country. Use the table further down to understand what kind of flies you will be facing, and the graphic below to know the time of year you'll need to stock up on fly supplies for your region!

When combating flies, you need to know what types of flies populate your area. Regional areas tend to see certain species regularly, but they can vary slightly due to changes in weather patterns and individual environments. Individual environmental factors mainly refer to how much water the plot of land holds, how near to a pond, or any body of water. Knowing the bug populations in your region aids in selecting a fly formula designed to combat those species; which is why some people might rave about a fly spray, but it doesn't work for another in a different region or just up the street.

Below we've included a loose guide from information gathered from the Department of Agriculture, the Smithsonian Institution, and individual state resources as to what types of flies populate different regions of the United States. These fly species are not limited to the regions listed below, but those regions regularly see the highest concentrations annually. You will not see house or biting stable flies in the chart below, as they are found throughout the entire United States due to being drawn to livestock, among other things.

Knowing which other fly species are drawn to different climates can also help predict what flies you might be up against this fly season. If the weather in your region is trending wetter or drier from the year before, you can still be ready with the right fly control to protect your horse.

Maintain a clean barn and stalls! Since manure is an attractive food source for many insects and their larvae, speedy removal of organic waste will reduce your barn's attractiveness to unwanted pests. Clean up manure and soiled bedding at least daily, as well as any leftover soaked feeds. Urine-soaked areas and manure piles are an inviting breeding ground for flies and mosquitoes; it is important to eliminate these breeding opportunities before they occur.

After mucking stalls, sweep the barn aisles of any debris. You may consider more frequent stall cleaning during the summer months when fly populations are at their peak. You can also consider adding barn curtains to your barn, which help prevent flies from entering in the first place. If your barn has a muck pile, try covering it with a plastic sheet to deter flies from getting into the moist environment and to keep rain from saturating it.

Work to eliminate puddles or areas of standing water around your barn that provide breeding grounds for insects. Leaky hose? Broken sprinkler? No water runoffs? Fix these issues to save water and reduce the possibility of fly growth.

Fly Traps & Repellents

Fly traps, fly tapes, and fly baits work by attracting flies using an appealing scent or visual. All of these repellents lure flies in to prevent them from escaping, or kill them through what they consume. Most require minimal setup, and depending on the trap and how many flies you have, some can last an entire season!

Fly traps work best if you can lure flies away from the barn and horses. Try placing them in different locations until you find an ideal place or two for catching the most flies. Fly tape can be hung in places where flies would most likely land, such as the ceiling or rafters of the barn. Fly baits can be sprinkled directly on the ground; however, they should not come in direct contact with your horses, children, or pets.

In your tack and feed rooms, the most important thing to keep in mind is proper ventilation. If electricity is available, bring in a fan to improve airflow and help reduce humidity. Store all grain in tightly sealed containers to discourage flies from helping themselves to a yummy snack. Remove or cover standing trash to prevent pests from hanging around.

Keep any perishable horse treats (apples, carrots, etc.) in a refrigerator, or ask your fellow riders to bring only what they intend to feed that same day. Finally, keep these areas as dry as possible. If you have plumbing inside your tack or feed rooms (such as a laundry sink or hose bib) make sure they drain well and are properly sealed with no leaks.

Air Circulation

A strong wind current from fans makes it harder for flies to travel through the barn. Consider hanging a box fan in your horse's stall to better prevent flies from landing on them. Even making this small change can keep your horse more comfortable during the summer months! With this method, you can also help prevent your horse from overheating, as improved air circulation provides a cooling effect.

Good pasture management practices will similarly help control pests. Rotate pastures to prevent overgrazing, mow tall grass and weeds, and regularly remove manure and debris. If possible, limit the number of horses in a single pasture to reduce manure build-up and minimize fly breeding sites. In addition, keep water sources clean and fresh to reduce algae growth (which attracts flies).

We completely understand that daily manure removal from your pastures and paddocks may not be a practical option. If this is the case, we suggest spreading out the manure so it does not build up in one area (think run-in shelters or your horse's favorite corner). Spreading manure across the pasture helps dry it out faster to make it less attractive to horse flies, mosquitoes, and other insects.

Fly sprays ward away flies by covering the horse with a layer of natural or synthetic insecticide or essential oils. Insecticides are a common ingredient for most sprays and roll-ons, as they are powerful repellents. Both horse fly sprays and topicals work to knock down flies; however, they must be applied regularly to be effective. Depending on the product, some must be applied daily while others that are sweat- and water-resistant can last up to a few weeks.

Natural Fly Spray

When talking about fly sprays, the term "natural" refers to formulas made without DEET, permethrins, pyrethrins, butoxypolypropylene glycol, piperonyl butoxide, and other pesticides. Instead, natural fly repellents often use different combinations of essential oils such as citronella, clove, cornmint, rosemary, eucalyptus, lemongrass, thyme, peppermint, and other botanicals. These botanicals all cause different reactions and effects in insects, either to repel or to kill. Some formulas also use ingredients similar to fatty acids or geraniol, which are known to have insect-repelling properties. Tea tree oil and neem oil are other popular alternatives.

Most natural fly sprays repel flies through spatial repellency; this means they create a "bubble" around your horse that flies don't want to cross. Chemical-based repellents work through tactical repellency, meaning flies have to land on the treated horse before they are repelled. Most natural fly sprays do not kill flies on contact but instead eliminate the contact altogether. Meanwhile, chemical fly sprays tend to both repel and kill insects.

Although natural fly sprays are effective, they will not last as long as chemical-based products. This is because synthetic products don't break down as quickly as natural ones; chemical insecticides are not as susceptible to degradation by UV light and oxygen, which breaks down ingredients. This means that natural fly sprays must be applied more often to be effective against flies, typically every eight hours or so. We recommend carefully reading the manufacturer's product label so you can ensure the best results from natural fly sprays. Most need to be shaken well before use to be effective, as the oils will separate.

DIY Fly Spray Cautions

With natural fly products rising in popularity, a multitude of do-it-yourself guides and recipes have cropped up online. While we don't want to deter anyone from considering a DIY fly spray, as they can be great options for some, they do come with added risks you should consider.

The biggest factor with making your own fly spray is the ratio of oils and other ingredients used. Ready-to-go bottles are carefully balanced to ensure that no single ingredient is concentrated enough to cause skin irritation or burns. Some oils and ingredients can be harmful in excess, or without the proper counter-ingredient. It can be tempting to alter the recipes, thinking that adding more of a certain ingredient you know works to repel pests will make your homemade spray more effective. In truth, too much of a good thing can accidentally harm your equine friend.

On the other hand, DIY fly sprays can be a great option for some horse owners because they provide the added peace of mind of knowing exactly what ingredients are being used, especially for those horses with sensitive or hive-prone skin. Our best advice is: if you think that DIY is your way to go, be sure to get your recipes from educated sources, follow them closely, and thoroughly research your ingredients before use.

Cost is another major factor when deciding whether DIY or ready-to-go fly sprays are best for you and your horse. Making a spray yourself may sound like it should be cheaper than buying something pre-made, but this is not always the case. Essential oils can be quite expensive, and when it comes to the amount you'll need to make bottles of fly spray, the cost can add up quickly. Also, not all essential oil brands on the market are 100% natural, because some contain synthetic materials and binding agents to make them more affordable. If you are considering the DIY route for the cleanliness of the products, keep these things in mind and be sure to do your research on your oils before purchasing.

Keep nagging flies and relentless bugs away with fly ointments, salves, and spot-on treatments, perfect for targeted protection. These repellents are designed for precise application on sensitive areas like the face, ears, and belly to create a long-lasting barrier for extended protection with easy-to-apply formulas.

When purchasing topical fly repellent, consider what kinds of flies you are dealing with. Some products target specific insect species; be sure to read labels carefully, then decide which is the best solution for you and your horse!

Fly sheets not only keep annoying bugs and biting insects off your horse, but can also protect them from UV rays—and even help keep them clean as an added bonus! Sheets with UV protection can be particularly useful for dark horses that spend a lot of time outside to prevent their coats from fading, or for very light horses that easily sunburn.

Fly masks are an easy way to keep bothersome bugs off of your horse's face. They reliably keep bugs out of sensitive areas, preventing common fly-related issues of watery, swollen eyes, or skin infection. Flies are attracted to the moist environment of a horse's nose, and fly masks with nose protection can help counteract insect-borne viruses in horses, as well as sunburned noses.

Horses can easily see through the mesh material over their eyes, and most will wear a fly mask willingly. There are different styles depending on the coverage your horse needs, and some fly masks specifically made for riding offer welcomed protection from flies while you hit the trails!

Fly boots cover the horse's lower legs, from the bottom of the knee or hock to the top of the hoof. Like fly masks and fly sheets, they are typically made of a mesh-like material that provides protection while allowing for airflow. Fly boots are particularly handy if your horse tends to stomp their legs at flies, and also if you are not able to fly spray them every day.

Selecting your horse's fly protection gear begins with a consideration of the styles, then materials, UV protection, and durability. Depending on your budget, the price can be an important factor as well. If your horse is hard on their clothing, it may be worth investing in a higher-quality item that holds up versus a lower-cost item that could demand more care or frequent replacement.

Wearable Material

Wearable fly gear for horses is typically made of one of the four following materials:

Ripstop Mesh - Made from nylon, these sheets are both lightweight and breathable. The ripstop design prevents new holes and tears from getting bigger, and the fabric offers up to 65% UV protection.

Tight Weave Polyester - Made of woven polyester, this material has a soft and comfortable feel but may not hold up quite as well if your horse is particularly rowdy. The tight weave provides up to 80% UV protection.

Textilene Mesh - Built to last, this material consists of vinyl-coated polyester designed to prevent rips, reduce heat transfer, and block up to 73% of UV rays.

Fine Window Screen Mesh - Protects against even the tiniest of bugs, such as gnats. This material is relatively durable and provides up to 65% UV protection.

UV Protection

UV protection is another feature to think about when choosing wearable fly gear for your horse. If your equine spends time outside and is prone to coat bleaching, a fly sheet with UV protection can help. If you own a horse with a light-colored nose that tends to get sunburned, a long-nose fly mask can help keep them protected during outdoor time.

Durability & Price

As many horse owners know all too well from experience, it is rare for fly gear to last more than one or two seasons. Whether it's too much rowdy playtime with other horses or just scratching an itch in their stall, your horse is sure to find a way to tear a hole in their fly sheet. Or they might have you hunting for their fly mask! If you have a playful or mischievous horse, it can be worth investing in fly masks with double-locking closures and fly sheets made of rip-stop fabric.

Whether you are on a budget or want to invest in the most advanced fly protection technology on the market, you will find a wide array of options available. Pricing for fly gear generally depends on the manufacturer's brand recognition, as well as the item's popularity and cost of materials. While higher-priced items are usually made from more durable materials, some lower and mid-priced products can work just as well!

Fly Gear Care

Caring for your horse's fly gear is simple: You can either rinse it off with a hose or place it in the washer on a light cycle, then lay it in the sun to dry. For storage during the off-season, pack up your fly gear and keep it in a cool, dry area—especially one where mice and other small creatures cannot cause any damage!

For more information on fly gear, watch our helpful video below!

Wearable fly protection is comprised of physical barriers that you place on your horse to prevent adult flies from landing directly on their skin. They typically include fly sheets, masks, and boots. Most fly gear is made from lightweight, breathable mesh materials to allow for better airflow during the warm summer months.

Some horses only need a fly mask to be happy; on the other hand, more sensitive horses may require additional protection to stay comfortable. Strategic features such as a belly band or full ear and nose coverage better protect your horse from the issues that can arise due to pests and intense sun rays.

Although barrier protectors must eventually be replaced due to wear and tear, they can be a great solution for boarding facilities that do not offer a broad fly control program. Can you and your horse not stand the bugs and need some fly gear while riding together? Take a look at our fly gear for riding!

Sometimes the pests in your area become so intense that your horse starts showing signs of being particularly bothered, such as constantly swishing their tail, stomping their feet, and shaking their head. If your equine is showing these behaviors while wearing their fly protection gear, they will need the additional protection of fly spray to better deter insects from landing on them in the first place. We suggest spraying your horse's gear with fly spray as well to double up the protection. Monitor your horse over time to determine the frequency at which you need to reapply your fly spray.

Natural fly sprays are precisely formulated for safety, stability, and ease of use. However, as with any product, horses can have sensitivities and allergies to certain ingredients in natural fly sprays. We recommend trying any new fly spray over a small area the first time you use it to ensure your horse tolerates it well.

Natural fly sprays that are DIY run a higher risk of irritation due to the margin for error in balancing ingredients. If you're using DIY recipes, be sure to follow them closely and obtain them from educated, reliable sources. Our equine experts typically stay away from DIY recipes and instead rely on natural fly sprays for horses from trustworthy brands like Equiderma, Absorbine, and more.