How to Stop Black Flies From Biting: Step-by-Step Guide

Quick answer

• Pack effective insect repellent with DEET or Picaridin.
• Wear light-colored, loose-fitting, long-sleeved clothing and pants.
• Use head nets for serious swarms.
• Time your outings for dawn and dusk when they’re less active.
• Check local conditions; some areas have seasons with fewer flies.
• Consider camping near moving water, which can deter them.

What to check first (do this before you drive out)

Before you even think about hitting the trail or setting up camp, get your ducks in a row. Black flies are no joke, and being prepared is key to a good time.

• Land manager / legality: Who’s in charge of where you’re going? Is it National Forest, BLM land, a State Park, or private property? Different agencies have different rules, especially for camping and fire. A quick look at their official website is usually enough. I learned this the hard way once, thought I was on public land, turns out it was private. Oops.

• Access/road conditions: Can your rig actually get there? Are the roads paved, gravel, or just a suggestion? Check for recent reports on mud, snow, or washouts, especially if you’re not in a high-clearance 4×4. Don’t be the guy who needs a tow truck.

• Fire restrictions + weather + wind: This is crucial. Are campfires allowed? What’s the forecast look like? High winds can actually help with flies, but you don’t want to be caught in a storm. Always check the local fire danger level and weather forecast.

• Water plan + waste plan (Leave No Trace): Where will you get potable water? Are there any potable water sources available, or do you need to pack it all in or filter/treat it? And remember LNT – pack out everything you pack in, including food scraps and trash. Know where the nearest trash receptacles are, or plan to haul it home.

• Safety (wildlife, distance to help, comms): What kind of wildlife might you encounter? How far are you from the nearest ranger station or town if something goes wrong? Do you have cell service? Consider a satellite communicator for remote trips.

Step-by-step (field workflow)

Alright, you’ve done your homework. Now it’s time to actually be out there and manage these biting bugs.

1. Arrive and Assess: Get to your destination and take a quick look around. Are the flies already out in force? What’s the general vibe?

• Good: You see a few flies, but nothing that makes you want to turn back.
• Mistake: Ignoring an obvious swarm and just plowing ahead. You’ll regret it.

2. Gear Up (Clothing): Put on your protective clothing. Think light colors, loose weaves, long sleeves, and pants tucked into socks or boots.

• Good: You’re fully covered, and the fabric isn’t sticking to your skin.
• Mistake: Wearing shorts and a t-shirt. You’re basically a buffet.

3. Apply Repellent: Treat exposed skin and the outside of your clothing with a repellent containing DEET or Picaridin. Follow product instructions carefully.

• Good: You’ve got a solid, even layer on all exposed areas.
• Mistake: Skimping on application or missing spots like your neck and ankles. They will find those spots.

For effective protection, consider a reliable DEET insect repellent like this one, which is highly recommended for deterring black flies.

4. Deploy Head Net (If Needed): If the flies are really bad, put on your head net. This is a game-changer for sanity.

• Good: The net is snug around your neck, and flies can’t get in.
• Mistake: Leaving the net unzipped or not securing the bottom. They’ll sneak in.

5. Set Up Camp Strategically: If possible, choose a campsite that’s not right in a dense, humid area. A spot with a bit of a breeze, or near moving water, can help.

• Good: Your tent is set up in a relatively open area with a gentle breeze.
• Mistake: Pitching your tent in a low-lying, damp area surrounded by thick brush. Prime black fly real estate.

6. Manage Food and Cooking: Keep food sealed when not in use. Cook downwind from your sleeping area if possible.

• Good: Food is in sealed containers, and cooking smells aren’t wafting directly into your tent.
• Mistake: Leaving food out or cooking right next to your sleeping spot, attracting flies.

7. Stay Active (Within Reason): While you don’t want to exert yourself to the point of sweating heavily (flies love sweat), a moderate level of activity can sometimes keep them at bay more than just sitting still.

• Good: You’re moving around, maybe doing some light chores, and the flies are following but not overwhelming.
• Mistake: Sitting perfectly still in a high-fly area. You become a stationary target.

8. Reapply Repellent: Check your repellent coverage periodically, especially after sweating or if you’ve been in water.

• Good: You notice the repellent feeling is fading and reapply.
• Mistake: Forgetting to reapply. The biting starts when the protection wears off.

9. Nighttime Routine: As dusk settles, flies often become less active. Secure your tent and enjoy the relative peace.

• Good: You’re inside your tent, zipped up tight, and the buzzing is minimal.
• Mistake: Leaving tent doors open late into the evening. They’ll find their way in.

10. Morning Check: Wake up and assess the fly situation. Be ready to adjust your plans if they’ve returned with a vengeance.

• Good: You see a few flies and can start your day with your gear ready.
• Mistake: Being surprised by morning fly activity and getting swarmed before you’re prepared.

Common mistakes (and what happens if you ignore them)

Mistake	What it causes	Fix
Relying solely on bug spray	Missed spots, repellent wearing off, leading to bites.	Use in conjunction with clothing and head nets. Reapply frequently.
Wearing dark, tight-fitting clothing	Attracts flies, easy for them to land and bite through thin material.	Opt for light colors and loose weaves that create a barrier.
Not checking local conditions	Arriving during peak black fly season unprepared or facing unexpected access issues.	Always check land manager websites and recent reports before you leave home.
Camping in humid, still environments	Creates ideal breeding and resting grounds for black flies.	Seek out breezy spots or areas near moving water.
Ignoring early signs of fly activity	Getting overwhelmed before you can properly gear up or adjust plans.	Be vigilant from the moment you arrive. Don’t underestimate their numbers.
Not securing head nets properly	Flies find their way inside, negating the net’s purpose.	Ensure the net is tucked in or sealed securely around your neck or shoulders.
Sweating heavily without protection	Attracts flies and makes repellent less effective.	Stay hydrated, move at a moderate pace, and reapply repellent after exertion.
Leaving food or trash exposed	Attracts flies to your campsite, increasing your exposure.	Keep all food and scented items sealed and stored properly. Pack out all trash.
Underestimating the power of a head net	Trying to tough it out without one when conditions are severe.	Invest in a good quality head net; it’s a sanity saver in heavy swarms.
Not having a backup plan for bad fly days	Ruining a trip or having a miserable time when flies are unbearable.	Have alternative activities or locations in mind if the black flies are too intense.

Decision rules (simple if/then)

• If the local ranger station reports “heavy black fly activity,” then pack a head net because they are likely to be overwhelming.
• If you see flies actively swarming around people, then immediately apply repellent and consider putting on protective clothing because they are already looking for a meal.
• If you are planning to camp near a slow-moving river in the spring or early summer, then be extra prepared for black flies because these conditions are ideal for them.
• If your skin is already red and itchy from bites, then reapply repellent and put on more clothing because you’ve likely lost protection in those areas.
• If the wind picks up significantly, then you might have some relief, but don’t pack away your repellent and head net just yet because they can still find you.
• If you are hiking in an area known for black flies and it’s humid and still, then expect them to be present and gear up before you even get out of the car.
• If you are cooking and the flies are swarming your food, then try to position yourself downwind of the cooking area or take a break until the food is put away.
• If you are considering a dip in a lake or stream, then be aware that black flies may be more active around the water’s edge and be ready to reapply repellent afterward.
• If you notice your repellent isn’t working as well as it used to, then it’s time to reapply or switch to a different product because effectiveness can decrease over time.
• If you’re planning a trip in late fall or winter, then you can generally relax about black flies because they are a seasonal pest.

FAQ

Q: When are black flies most active?

A: They are typically most active in the spring and early summer, especially during the warmer parts of the day. Dawn and dusk can be prime biting times.

Q: What’s the best repellent for black flies?

A: Look for repellents containing DEET (20-30% concentration) or Picaridin (15-20% concentration). Permethrin can be used on clothing and gear for added protection.

When choosing a repellent, look for products with DEET (20-30% concentration) or Picaridin, such as this effective DEET insect repellent.

Q: Can I just wear a t-shirt and shorts?

A: It’s a bad idea. Black flies can bite through thin fabrics and will target any exposed skin. Long sleeves and pants are your best bet.

Q: Do black flies carry diseases?

A: In North America, black flies are generally not known to transmit serious diseases to humans, but their bites can be painful, itchy, and cause allergic reactions in some people.

Q: Are there any natural remedies that work?

A: Some people find essential oils like citronella or eucalyptus helpful, but their effectiveness is often less reliable and shorter-lived than DEET or Picaridin.

Q: What if I get a lot of bites?

A: Clean the bites with soap and water. Apply a cold compress, hydrocortisone cream, or an antihistamine to reduce itching and swelling. Avoid scratching.

Q: Can I use a fan at my campsite?

A: Yes, a small portable fan can help create airflow that discourages flies from landing and biting. It’s a nice addition if you’re car camping.

Q: What’s the difference between black flies and mosquitoes?

A: Black flies are smaller, stout-bodied, and bite by slicing the skin and lapping up blood, causing a more painful, often bleeding bite. Mosquitoes have a proboscis they use to pierce the skin.

Q: Should I avoid camping during black fly season?

A: Not necessarily. With proper preparation and gear, you can still enjoy camping. Just be aware of the season and take precautions.

Q: How can I tell if I’m having an allergic reaction?

A: Severe swelling, hives away from the bite area, fever, or difficulty breathing are signs of a more serious reaction. Seek medical attention if you experience these.

What this page does NOT cover (and where to go next)

• Specific black fly species and their exact life cycles. (Check local entomology resources.)
• Detailed medical treatments for severe allergic reactions. (Consult a healthcare professional.)
• Reviews of specific camping gear brands or models. (Look for gear reviews from outdoor publications.)
• Legal regulations on insect repellent use or disposal. (Refer to product labels and local waste guidelines.)
• Advanced techniques for tracking insect populations. (This is usually for researchers.)