Biting flies are a nuisance all over the world. These insects, in their quest for blood, target humans, pets, livestock, and wildlife, making them more than just a mere annoyance. Beyond the immediate pain and itch, some biting flies are vectors of disease, adding a layer of health concern to their presence. Understanding the types of flies that bite is the first step in protecting yourself, your family, and your animals.
Deer Flies: The Painful Pinch
Slightly smaller than the common house fly, deer flies emerge with the warmer weather of spring and are notorious for their painful bites. Unlike flies that pierce the skin, deer flies possess scissor-like mouthparts that literally slice into the skin to access blood. This cutting action is what makes a deer fly bite so instantly and intensely painful. Their persistence in pursuing a blood meal, often circling their target, can be quite irritating, especially in outdoor settings like wooded trails or near water.
Horse Flies: Large and In Charge (and Painful)
Horse flies are the heavyweights of the biting fly world, both in size and bite severity. Similar to deer flies, they also use a slice-and-lap feeding method, causing a painful wound that can often bleed and swell. The sheer size of these flies, often buzzing loudly as they approach, can be intimidating. Horse fly bites are frequently cited as among the most painful insect bites one can experience in many regions.
Do Horse Flies Bite Dogs? Pets and Horse Fly Bites
While any fly bite can be irritating to dogs, horse flies and deer flies are particularly bothersome due to their painful bites. A large number of bites can cause significant skin irritation in dogs, leading to excessive scratching and potential secondary infections. Female horse flies are the blood-feeders, requiring protein from blood for egg production, while males feed on nectar. Warm temperatures are their preferred activity period, but unlike some smaller flies, horse flies are less deterred by breezes because of their robust size.
Dogs, in their attempts to relieve the irritation, may scratch or bite at the bite sites, potentially causing injury and open wounds. These wounds can unfortunately attract more flies, and in severe cases, flies might even lay eggs in open wounds, leading to a condition called myiasis (fly larvae infestation). If you observe signs of wound infestation, immediate veterinary attention is crucial. For pets prone to fly irritation, limiting outdoor exposure during peak fly activity hours, particularly during warm daylight hours, is advisable. Short, supervised outings are preferable. If flies are persistently bothering a pet’s ears, consulting a veterinarian for appropriate treatment and fly repellent options is recommended.
Black Flies: The Tiny Terrors of Flowing Water
Black flies, often found swarming near rivers and streams, are small but persistent biters. Their characteristic humped back is a key identification feature when viewed closely. While found across the United States, they are especially prevalent and bothersome in northern states, where their populations can explode in spring and early summer. Black flies also slice the skin to feed on blood, and while their bites might seem less immediately painful than a horse fly bite, they can cause significant itching and welts. Some people experience allergic reactions to black fly bites, resulting in more pronounced swelling and discomfort.
Stable Flies: Lookalikes with a Piercing Mouth
Stable flies bear a striking resemblance to house flies, often leading to misidentification. However, unlike house flies which are primarily nuisance pests, stable flies are blood-feeders. The key distinguishing feature is their pointed, forward-projecting mouthpart, designed for piercing skin and sucking blood. They are most common in late summer and fall and are frequently found around livestock facilities, as their name suggests. Stable flies are persistent biters and are known to bite humans as well, particularly around the ankles and lower legs. Their bites can be quite painful and itchy, and they are known to be aggressive and persistent in seeking a blood meal.
Snipe Flies: Mostly Benign, But Some Bite
Snipe flies are related to deer flies and are typically found in damp, wooded habitats. The majority of snipe fly species are not biters, with adults feeding on nectar or not feeding at all. However, certain species within this fly family do possess mouthparts capable of delivering an irritating bite. These biting snipe flies are less aggressive than deer flies or horse flies, but their bites can still be noticeable and cause localized discomfort.
Sand Flies: Tiny Size, Intense Bite
Sand flies, sometimes confused with drain flies due to their small size, are tiny but their bites pack a disproportionate punch. Adult sand flies are minute, often less than 1/8 inch long, with long legs and wings held in a distinctive V-shape at rest. They target mammals and reptiles for blood meals. Despite their diminutive size, sand fly bites are notoriously painful and can cause significant itching and skin irritation that can last for days. In some regions, sand flies are also vectors of diseases like leishmaniasis, making them a significant public health concern.
Yellow Flies: Southeastern Biting Specialists
Yellow flies are primarily found in the southeastern United States and are particularly fond of shaded areas near forests and water bodies. They are aggressive biters, and their bites are followed by localized swelling, intense itching, and sometimes prolonged discomfort. Similar to deer flies and horse flies, they use a cutting and lapping mechanism to feed on blood. Their preference for shaded habitats means they can be encountered even during the hotter parts of the day when some other biting flies might be less active in direct sunlight.
Biting Midges (No-See-Ums): The Pervasive Pinpricks
Biting midges, often referred to as “no-see-ums” or “punkies” due to their incredibly small size (rarely exceeding 1/32 of an inch), are masters of infiltration. They can easily pass through standard window and door screens, making them a common indoor biting pest, especially in coastal areas. Biting midge larvae thrive in moist environments like mud and salt marshes. Adults are most active on calm days as they are weak fliers susceptible to air currents. Their bites, while individually tiny, can be numerous and cause intense itching and irritation, often leaving behind small red bumps.
Mosquitoes: The Infamous Disease Vectors
Mosquitoes are arguably the most well-known biting flies and are responsible for biting more people globally than almost all other biting fly species combined. Their notoriety stems not just from their itchy bites, but also from their role as vectors of numerous diseases. Mosquitoes transmit serious illnesses such as West Nile virus, Zika virus, malaria, and dengue fever, making them a significant public health concern worldwide. Unlike the slice-and-lap feeders, mosquitoes use a piercing proboscis to puncture skin and draw blood.
Problems Caused by Flies that Bite: Beyond the Bite
The problems associated with biting flies extend beyond the immediate pain and itch of their bites. Allergic reactions to fly bites can occur in some individuals, leading to more severe skin reactions. Furthermore, as highlighted with mosquitoes and sand flies, certain biting flies are vectors of diseases that can affect both humans and animals. Deer flies, for instance, are known to transmit tularemia.
Livestock are also significantly impacted by biting flies. Beyond disease transmission, swarms of biting flies can cause constant irritation and agitation in cattle, horses, and other livestock, impacting their health, productivity, and well-being. The economic impact of biting flies on agriculture and animal husbandry can be substantial.
Getting Rid of Biting Flies: Control and Prevention
Effective biting fly control focuses on disrupting their breeding habitats and implementing personal protection measures. Mosquitoes, for example, require standing water to breed, so eliminating sources of stagnant water around homes, such as emptying containers, cleaning gutters, and ensuring proper drainage, is crucial for mosquito control. For other biting flies that breed in decaying organic matter, maintaining clean environments by promptly removing trash, cleaning up yard debris, and managing compost piles can help reduce populations.
For proactive fly control and relief from existing infestations, contacting pest control professionals like Orkin is a recommended step. Trained professionals can accurately identify the specific types of biting flies causing problems and implement targeted and effective fly control strategies, ensuring both immediate relief and long-term prevention.
