Fun Fly Facts

Are you and your horse plagued by flies? Take our quiz to test your fly IQ.

Are you and your horse plagued by flying pests? Take our quiz to test your fly IQ and boost your fly defense.

The sun’s out, and skies are blue—for most of us, summer is just around the corner. If you’re like most horse owners, that means it’s time to trade your horse’s heavy winter blanket for a fly sheet, start stocking up on fly-repellent sprays, and get ready to launch your annual War on Flies. The ancient Chinese expression “know thine enemy” certainly applies here.

When it comes to waging war, you can never know too much about the other side. So, if you want to win that War on Flies, grab a pencil and take our quiz. Then check your answers on page 54. Chances are, you’ll learn some fun fly facts to share around the barn and boost your fly-warfare expertise. →

move is the challenge. Picture this scenario: You’re riding your horse, when he starts being chased by a determined bot fly. If you’re like me, you’ve probably dismounted on a few occasions so you could chase the fly around in circles in an attempt to swat it. Frustrating, right? Next time, consider breaking into a gallop (or even a brisk trot) to escape the annoying pest.

Question 5: Answer A

A female fly typically may lay as few as 75 to 100 eggs per “batch,” but that’s only the beginning of the story. A female will begin laying eggs 10 to 12 days after she matures, and she can lay five or six batches in her lifetime. These eggs will hatch in less than a day. A group of scientists calculated how many flies would accumulate over time if a single pair were allowed to breed completely unchecked (i.e., all of their offspring survived). The results were astonishing. In just five months, that pair of flies would result in 191,010,000,000,000,000,000 family members—enough to cover the entire surface of the earth, several meters deep. So when considering your War on Flies, pay particular attention to their breeding grounds. Flies like to breed in moist, dark areas, ideally surrounded by trash or manure. By picking up trash, cleaning up manure, and taking steps to control mud, you’ll minimize their ability to reproduce.

Question 6: Answer B

Flies have compound eyes, made up of thousands of tiny individual lenses called ommatadia. This provides a very wide field of vision. A fly can see 360 degrees around his body at all times. Why is this important for your War on Flies? No matter the direction, flies can see you coming when you try to swat them. Add to this their lightning-fast reflexes (they see you coming and make a decision about which way to jump within 100 milliseconds of when you first move), and it’s easy to understand why it’s hard to kill a fly. If you want to be successful, you must plan ahead. Researchers studying fly reactions suggest planning which way a fly is most likely jump ahead of time (often backward) and swat accordingly.

Question 7: Answer C

A fly sucks up his food in liquid form through a proboscis, a tubular extension of the mouth similar to a straw. So how does he feed on solids? He uses a combination of saliva and stomach contents (“fly vomit”) to liquefy the surface so he can slurp it up. Disgusting, right? This fun fact might not help you wage your War on Flies, but it should provide plenty of motivation for keeping them away. And what about the flies that bite, such as deer flies and horse flies? Biting flies are typically blood feeders—they bite to gain access to a liquid blood meal. These bites are not only painful; blood-feeding flies are particularly dangerous as they’re most likely to spread serious diseases such as equine infectious anemia.

Question 8: Answer B

Flies are incredibly agile and maneuverable. They can not only hover and fly in all directions, but also jump backward when they perceive a threat. They even have small “rudders” next to their wings (called “halteres”) that help them to stay oriented when performing these acrobatics. And while it may seem that flies travel completely randomly, scientists have shown that flies’ flight patterns aren’t random at all. In fact, the typical flight pattern involves repeating straight lines and 90-degree turns that allow them to locate the source of odors they’re attracted to as potential food sources. The fact that this pattern seems random to observers gives the fly a big advantage when it comes to avoiding predators. Given their incredible agility and lightning-fast reflexes, it’s no wonder pesky flies are such formidable enemies.

Question 9: Answer A

Fly repellants can be effective can or not. be Studies effective…or have shown that resistance not. to

insecticides used for controlling flies is highly variable depending on geographic location and the specific populations of flies. That makes efficacy very hard to predict. Does that mean that fly sprays are completely worthless? Absolutely not. But trial-and-error is probably the most effective strategy to help you determine if a fly repellent is working for your horse. And be aware: A fly spray that works great at home might be less effective when you’re away from home, due to location-based resistance. Most importantly, the variable efficacy of fly repellants points out the need to have multiple weapons available for your War on Flies. no matter how hard to you try to eliminate breeding grounds and control populations, where there are horses, there will be flies.

Question 10: Answer C

It may be hard to believe, but flies actually have quite a bit to offer the world—starting with their disgusting eating habits. They not only “vomit” on their food to encourage decay, they follow up by eating it. And when they lay their eggs in piles of trash or manure, those eggs hatch into maggots that help to further break down decaying matter. In fact, maggots have seen a resurgence in popularity as a medical “device” that can be used to help debride infected wounds and encourage healing. Flies have other benefits as well. They do participate in pollination, and they feed on other pests like aphids that can infect the roses in your garden. Finally, flies are very low on the food chain, and provide nutrients for other important species such as birds, bats, and fish. 