Your first impression of horse flies might be innocent enough – they’re often confused with regular flies. That is, until they bite! The horse fly is a voracious feeder, and a swarm of females can relieve victims of as much as 2 cups (1 pint) of blood in less than a day.

Like another loathed summer pest, the mosquito, horse flies require a body of water (preferably stagnant) to breed. And females require a blood meal from a victim before they can reproduce.

Horse flies have found their niche in the livestock community. Since bodies of water and large warm-blooded mammals such as horses and cattle are often found together, horse flies tend to gravitate toward areas that offer both. This, of course, is how the horse fly got its name. This also explains why we tend to notice them more when we’re hanging out at the lake or pool.

How to Spot a Horse Fly

In flight, a horse fly is easily mistaken for a house fly. However, when they land, you can see how much bigger they are. Horse can be anywhere from ¾ inch to 1 inch long. They typically have clear or colored wings with bright green or black eyes. Horse flies are active during the day and prefer to fly in direct sunlight. Movement, warmth, shiny surfaces, and exhaled carbon dioxide draw the attention of the female in an attempt to find a blood meal. Males feed only on nectar and do not suck blood (thanks, guys).

Horse Flies Bite!

Female horse flies actually have scissor-like jaws (gross!) that slice your skin to get to your blood. Then she will lap up the blood similar to how a dog might lap up water (even grosser!). This explains why you will certainly notice a horse fly bite immediately. They’re painful!

Horse flies have also been recognized as a carrier for many infectious diseases, most notable swamp fever, or Equine Infectious Anemia (EIA). Thankfully, EIA does not affect humans – only equine animals – however, it can be life-threatening to our equine friends.

Fending Off a Horse Fly

We have another bit of bad news about horse flies. It is generally quite difficult to fend of hungry horse flies, since they don’t respond to insect repellants, even ones that contain powerful chemicals such as DEET or Picaridin.

Some biting insects, such as mosquitoes, are dainty and fragile, but that is not the case with the robust and hardy horse fly. While a single well-placed swat may send a mosquito to misery, a horse fly may pursue its chosen prey for miles without ceasing. (Talk about dedication!)

The best way to minimize the risk of being bitten by horse flies is to stay inside. However, it’s summer and we know you want to swim or go fishing with your buddies. While you’re out, wear heavy clothing and hats to make it more difficult for a horse fly to bite. Carry a fly swatter and practice your aim.

Preventing horse fly infestation is also important. You can do this by eliminating bodies of water that may serve as breeding grounds, or kill all the flies while in the larval stage. Not only will eliminating bodies of water help reduce your chances of getting bit by horse flies, but it will help reduce mosquito populations as well.

Contact YES Pest Pros for Help

If horse flies (or any other creepy-crawlie) is really “bugging” you this summer, give us a call. YES Pest Pros has developed an eco-friendly approach to residential pest management. This system includes the use of green pest management substances, inspection to eliminate breeding sites, and sanitation to keep more flies from entering the area. Give us a call or send us a message today for more information.