Hiking Through Black Fly Season Without Getting Bit


Hike through the Northeast United States throughout the summer and you’ll have to deal with black flies. Although black flies are small, there bites pack a serious punch. Get caught in a swarm of black flies and it’s going to be painful. If you’re not careful you’ll end up with more bites than you can count.

Watch Out For Black Fly Season

Peak black-fly season runs from March through the middle of July. They can be found throughout Pennsylvania, Ohio, Michigan and the entire New England area. Growing up in Ohio I’ve had to deal with black flies my entire life.

You Can’t Avoid Them!

I think it’s crazy that some backpackers, campers, and fishermen avoid black fly season. They’re missing out on some of the best weather of the year. It’s crazy how many people stay home so they won’t have to deal with bugs. While they stay home the rest of us thank god it’s spring, suck it up and grow a pair.

Why Do Black Flies Suck?

Black flies are like really big painful mosquitos. They travel in big swarms and live off blood like little vampires. Head to your local farm and I guarantee you’ll see swarms of flies feasting in horses/cattle.

Females Bite: The females bite, while the males mostly feed on nectar. You’ll find black flies wherever there are animals and moving water.

Where Will I Find Black Flies?

If you’re hiking throughout late spring, early summer you will run into black flies. They’re most active in the early mornings and just before dusk while the humidity is high.

Flies seek out moisture so you’ll find them near just about any water source. When the air is dry they’ll seek out moisture found on nearby leaves and trees.

Black Flies Breed in Moving Water

Unlike mosquitos that breed in stagnant water, flies lay their eggs in fast-moving water. They’re commonly found in moving rivers and streams in heavily wooded areas.

Black fly eggs are attached to rocks, survive throughout winter, just waiting for the spring thaw. They sit and wait for food to pass by growing until they finally emerge as adults come spring.

These are the flies that fly-fisherman replicate. Trout love to feed on fully grown flies. Go camping, hiking or fishing during spring/summer and I guarantee you’ll find a few swarms.

Do Black Flies Spread Disease?

Although their bites are painful, there’s no proof black flies spread disease like other biting insects. However, the bites are itchy, extremely painful and cause severe allergic reactions in a large percentage of people. I actually get a softball-sized lump after getting bit.

They’re Not The Same as Horse Flies

Like horseflies, black flies have an extremely painful bite. While their bite is similar to horse flies, adult black flies prefer human blood over an animal. They crawl up your sleeves, into your pants, above your boots and below the brow line.

Get a bite and I guarantee you’ll be sore and swollen for a few days. People/animals have even been killed by swarms of black flies.

How to Avoid Black Flies

It’s almost impossible to completely avoid black flies in the spring/summer. You can’t hide indoors throughout the entire black fly-season. Here’s how you should avoid black flies.

Flies bite in shady areas throughout the day and get particularly active early-mornings and before dark. I have no idea why, but they won’t bite inside or late at night.

Environmental Factors

  • Hike Mid-Day: Avoid early-morning and late-evening hikes. That’s when black flies are especially dangerous.
  • Avoid Humidity: When it’s low-humidity, black flies head towards moisture. They hide on/under leaves, moss, and anywhere else they find moisture.
  • Moving Water: Avoid trails that run along streams, rivers, and creeks. That’s where black flies lay their eggs and tend to swarm.
  • Head Towards Open Water: Setup trips around open water. Lakes and ponds are less appealing to black flies. They hate wind and stagnant water.
  • Windy Weather: Wind makes it hard for flies to smell out blood. When they can’t track down the food they try to save energy.

Keeping Away Flies

  • Wear Long-Sleeves: Wear long-sleeve shirts and long pants to protect yourself from bites. Go with one of those button-down hiking shirts that you see at REI.
  • Close Up Your Shirts: Proper clothing offers protection against flies. Keep your shirts buttoned/zipped, pants tucked and trousers inside socks. Zippered shirts work better than buttons.
  • Light Colors: For some reason, flies are attracted to dark colors. They’re attracted to blues, purples, browns, and blacks. Stick to light-colored shirts(white/yellow) since you rarely find light colored animals in the wild.
  • Build a Fire: Startup a fire before the sun goes down and flies get active. Campfires will keep away flies and mosquitos.
  • Use Insect Repellents: Insect repellants containing DEET are best at keeping away flies and mosquitos(Go With Deep Woods). Natural insect repellants with lavender, pine and vanilla are known to keep away insects. I’ve had a lot of success with Baby Skin So Soft bath oil.
  • Avoid Strong Deodorant/Perfume: Flies go after anything that smells sweet. Using strong-smelling deodorant and perfume will attract flies and mosquitos.

Be Careful! Bites Sting!

Once the black fly bites you it’s going to bleed and sting. The bite starts off small/red with a central spot and quickly swells. As the infection spreads it becomes itchy and swollen often lasting for days/weeks.

You can get temporary relief with anti-itch creams and anti-histamines. Be careful with an anti-histamine cause they can make you drowsy.

How to Treat Black Fly Bites

Black fly bites are slow to heal, but you can lessen the pain. There are lots of different anti-itch products on the market. Head to your local CVS and ask the pharmacist for a recommendation.

He will probably recommend some type of calamine lotion or aloe vera based product. These products will significantly reduce pain/itching.

On The Trail Treatment

I always keep a small tube of Zinc Oxide in my pack(I like Desitin) just in case I get a bad case of Monkey Butt. Zinc Oxide will help treat most minor skin rashes and infections. It has a wide variety of uses on the trail.

Check out my post on the different uses of Zinc Oxide on a hike.

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