Horse Illustrated Magazine

Keeping insects away from your horse and out of your barn can seem an exercise in futility at times. While there are loads of fly-control products on the market, everyone seems to have a theory about what else can be done to keep bugs at bay.
Here’s the down-and-dirty truth about what doesn’t (and does!) keep bugs from bothering your equine friends.

Theory: Placing a penny in water in a resealable baggie and hanging it from a doorway will keep flies from entering your barn.

Conclusion: False. While the thought process behind this theory is intriguing, the method sadly doesn’t work. It’s purported that the copper penny in the water creates a prismatic effect on a fly’s eyesight, and the dizzying spectacle keeps them from approaching your horse’s dwelling.

Theory: Long, cold winters will kill off over-wintering fly populations.

Conclusion: False. Entomologists report that over-wintering fly populations can survive deep in the soil; heavy snow cover can actually protect these flying insects from extreme cold. Additionally, a cold winter followed by a warm and sunny March could actually accelerate some fly cycles—what an unfair scenario!

Theory: Electric bug zappers stop flies in their tracks.

Conclusion: False. While the noise bug zappers make when they fry bugs can seem satisfying, they really do more harm than good by killing thousands of beneficial insects that don’t bother people or horses, leaving the majority of flies alive to pester us.

Theory: Ultrasonic devices will keep flies and other rodents away from your barn.

Conclusion: False. Ultrasonic pest repellers emit high-frequency sounds (above the range of human hearing) designed to repel or kill insects and rodents. Sadly, laboratory tests have shown that the majority of these devices do not work.

Theory: Vanilla-scented air fresheners repel flies and leave your barn smelling sweet.

Conclusion: False. Vanilla-scented car air fresheners may not very helpful as fly repellent in the barn, but pure vanilla has been reported to repel mosquitoes (but the sweet smell may attract bees!).

Theory: Bacon grease will help repel flies.

Conclusion: True. Because of its viscosity, bacon grease applied to the horse where flies tend to bite will result in rapid relief. Additionally, should the horse have open sores where flies have bitten him, the grease will not irritate the open wound. Petroleum jelly, also sticky, can work as well.

Theory: Dryer sheets can help repel flies when riding.

Conclusion: Possible. Though more likely to repel mosquitoes and gnats, dryer sheets contain two chemicals, linalool and beta-citronellol, that may repel flying insects. It couldn’t hurt to tuck one into your pocket or under your saddle to see for yourself!