Biting Flies: How to Repel Them and Treat Bites

Insect Shield helps prevent diseases transmitted by flies.

Flies are unavoidable and with an estimated one million species on earth, it’s easy to imagine why. Flies are insects with just one set of wings – although they do have a second set of underdeveloped “hindwings” for balance – and the order known as Diptera includes gnats, midges, and mosquitoes.

Flies, including mosquitoes and others, can spread serious diseases—and are said to be the source of more human illness and death than any other organisms except transmitted pathogens and people themselves. In addition to mosquito repellent clothing for men, women and kids, Insect Shield offers two forms of mosquito clothing treatment, our permethrin spray for clothes, and our clothing treatment service called Insect Shield Your Own Clothes: send us your favorite clothes and we will treat them with permethrin repellent and send them back to you!

Houseflies are not only a nuisance to people, they can spread the parasite that causes dysentery. They also are believed to contribute to the spread of typhoid fever, cholera, and other diseases throughout the world.

Which Types of Flies Bite?

Many types of flies bite people and animals to feed on blood. Mosquitos are the best known biting fly. Only the females bite to reproduce and mosquitos bite more people than any other species and spread diseases such as Zika virus, West Nile virus, dengue, and malaria. Deer flies and horse flies cut the skin with scissor-like mouthparts and their bites are known to be painful. Sandflies are small flies that use long, piercing mouthparts to suck blood. Midges are tiny biting flies that live and breed near water. Other biting flies include black flies, yellow flies, and drain flies.     

How to Prevent Bites from Flies

The best way to prevent flies from biting is to know what attracts them and to cover up when you are out when they are. For example some flies are attracted to decaying organic matter, while others are attracted to a blood source’s scent. 

Here are some easy ways to prevent flies from biting:

  • Cover up - clothing and gear treated with permethrin - such as Insect Shield - is a tested and proven defense against biting flies
  • Use insect repellent like DEET
  • Avoid swampy, muddy areas where biting flies lay eggs 
  • Reduce vegetation and standing water around your home
  • Use mosquito netting if you are traveling to a place with mosquito-borne illnesses

How to Treat Bites from Flies

Most fly bites are harmless. They may cause itching and swelling, but your symptoms should go away in a few days. If you are bitten in areas where mosquito-borne illnesses are commonly transmitted, seek medical advice and keep a close eye on symptoms. 

Here are some things you can do at home to relieve fly bites:  

  • Clean the bite area with soap and water
  • Use hydrocortisone or calamine lotion 
  • Try an oatmeal bath
  • Ice the swelling
  • Take over the counter antihistamine 

What Diseases are Caused by Flies?

When flies bite it’s mostly uncomfortable, but most bites pose no serious health risk. However, there are species that can transmit diseases to humans and animals. In rare instances deer flies can transmit tularemia, a bacterial disease also called deer fly fever, but this mostly affects mammals and birds. Horse fly bites can get infected, but they are not known to carry disease in humans. 

The Simulium blackfly can carry an infection called onchocerciasis, a dangerous disease that can produce skin disease and vision loss. In 2017, over 20 million people became infected worldwide. The vast majority of infections occurred in countries in Africa. Travelers in these areas need to be aware of the risks. More information can be found on the CDC website.