Deer Fly

Deer Fly

Deer flies are named because they commonly feed on the blood of deer, along with horses, livestock, and other mammals. There are approximately 350 species of deer flies found throughout North America.

Pest Identification

Adult deer flies can grow to be about ΒΌ- 1/3 of an inch in length. They are light brown to gray in color with some species having yellow or black striping. Deer flies have clear wings with dark banding or spots; their eyes are brightly colored and their antennae are longer than their head.


Females lay their eggs throughout the summer months in marshy or wet areas on leaves, rocks, or low overhanging trees. After about 5-12 days the larvae will emerge and burrow themselves in the soil and begin feeding on organic materials. They feed throughout the winter and in the spring once the soil begins to dry the larvae will pupate for 6-12 days. Adult deer flies then emerge and begin feeding and breeding. Deer flies can transmit a variety of diseases to people that include Lyme disease, Equine Infectious Anemia, and others. When a female deer fly bites their victims they often inject an anticoagulant which can cause a severe allergic reaction in some people.


Deer flies are found inhabiting areas that are open and have a lot of animal activity. They are commonly found in both suburban and rural areas. They also prefer areas that have a lot of sun and are close to water sources. Males feed on plant pollen and nectar; it is only the females that feed on the blood of vertebrae species. They require the protein found in the blood to produce their eggs. Females will find their prey by detecting them through site or through the carbon dioxide and/or body odor that they give off. Deer flies generally attack the head and neck of their victims and will leave behind a raised, red itchy welt.


The best way to protect yourself from being bitten by a deer fly is to use insect repellents, wear light-colored clothing, and wear a hat when spending time outdoors. It is also a good idea to make sure that screens are used in windows and doors of your home, and to not leave exterior doors open for a long periods of time.


Controlling deer flies is a tough task; Rottler can help through our Signature pest control program. Our professionals can recommend and install appropriate measures to eliminate deer flies in your home or business using baits and/or insect light traps in the appropriate areas to try and limit the number of deer flies infesting your property.

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