Anyone who has been in the Maine woods in early June knows the black flies are not a nuisance, they are a force of nature. They come in clouds, they crawl into your hairline and behind your ears, and they bite hard enough to draw blood and leave a welt that itches for days. Mosquitoes take over the evening shift and run all summer. Bug spray helps, but there is a point, usually somewhere in the 100-Mile Wilderness in mid-June, where spray alone is not enough and you want a physical wall between the bugs and your skin.
That wall is a head net or a bug shirt, and the single thing that matters most is mesh fineness. Here is the catch that trips people up: black flies and no-see-ums are tiny, and they walk straight through ordinary mosquito netting. A net that stops mosquitoes can be useless against Maine black flies. So the short answer is to buy mesh fine enough for no-see-ums. The Sea to Summit Ultra-Fine head net is the finest here at 2,000 holes per square inch. For full coverage, a bug shirt like the Original Bug Shirt wraps your whole upper body, and for everyday wear, a permethrin-treated hoody fights bugs and sun at once.
| Gear | Price | Best For | Type | Mesh |
|---|---|---|---|---|
| Sea to Summit Ultra-Fine | Mid-range | Black flies, no-see-ums | Head net | 2,000 holes/sq in |
| Coghlan's No-See-Um | Budget | Cheap black fly net | Head net | Fine no-see-um |
| Ben's InVisiNet | Budget | Clear vision | Head net | Fine knit |
| Original Bug Shirt Elite | Premium | Full coverage, no chemicals | Bug shirt | No-see-um face |
| ExOfficio BugsAway Hoody | Premium | Treated everyday wear | Permethrin clothing | N/A |
| Bug Baffler Shirt | Mid-range | Affordable full coverage | Bug shirt | Fine mesh |
Why Won’t a Regular Mosquito Net Stop Maine Black Flies?
Because black flies and no-see-ums are smaller than mosquitoes, and they slip through mesh that a mosquito cannot. Mesh fineness is measured in holes per square inch, and the threshold matters. A standard mosquito net might have 300 to 500 holes per square inch, which sounds like a lot and stops mosquitoes fine. Black flies and no-see-ums walk right through it.
For Maine’s black flies, you want no-see-um grade mesh, which runs roughly 1,000 holes per square inch and up. The Sea to Summit Ultra-Fine net sits at 2,000, which is about as fine as head nets get and is explicitly rated for the smallest biting insects. This is the one spec where the cheap option can genuinely fail you, so check it before you buy. A net that is comfortable and easy to see through but lets the bugs in is worse than no net at all, because it lulls you into not spraying.
Watch out for the standard versions of otherwise-good nets. Sea to Summit and Coghlan’s both sell a basic mosquito net alongside their fine no-see-um net, and the standard versions, around 300 to 500 holes per square inch, are mosquito-grade only. They will not keep Maine black flies off you. Buy the no-see-um or ultra-fine version specifically.
The Bug Nets and Clothing We Recommend
Sea to Summit Ultra-Fine Mesh Head Net - Best for Black Flies
If you want one head net that actually beats Maine black flies, this is it. The mesh runs 2,000 holes per square inch, the finest on this list, and it is rated specifically against the smallest biters: midges, sandflies, and no-see-ums, the same size class as black flies. This is the net you reach for when the bugs are at their absolute worst.
It weighs almost nothing at 0.8 ounce and packs into its own tiny stuff sack, so it lives in a pocket of your pack all season and you forget it is there until you need it. The mesh is black, not white, which sounds like a small thing but matters a lot: black mesh nearly disappears when you look through it, while white mesh fogs your vision and makes you feel like you are walking around in a veil.
The honest limits of any head net apply here. It protects your head and neck only, not your arms or torso, and like all head nets it can rest against your face if you do not wear a brimmed hat underneath to hold it off your skin. Bugs will bite through mesh that touches you. Wear a hat under it and this is the gold standard for Maine bug season.
The finest-mesh head net for Maine black fly season
Coghlan’s No-See-Um Head Net - Cheapest That Works
Coghlan’s makes the head net you can throw in every pack, glovebox, and tackle box for a few dollars. The key is to buy the No-See-Um version specifically, not the standard Coghlan’s net, because only the No-See-Um mesh is fine enough to stop black flies. The standard one is mosquito-grade and will let you down in June.
Get the right version and it does the job. The fine mesh keeps black flies and no-see-ums out, it fits over a hat, and it seals at the neck with an elastic edge. For the price, it is the easy answer to “I should really have a head net” without thinking twice about cost.
It is a basic piece of gear and shows it. There is no stuff sack, no structure to hold the mesh off your face, so a brimmed hat underneath is even more important here than with the pricier nets. But as cheap insurance against a ruined trip, it is hard to argue with. Buy two.
The cheapest head net that actually stops black flies
Ben’s InVisiNet Head Net - Best Visibility
The complaint people have about head nets is that they feel like looking at the world through a screen door. The InVisiNet is built to fix that. It uses a very fine knitted mesh that you can almost see straight through, so your vision stays clear while the bugs stay out. If you have skipped wearing a net because you hated the way it looked, this is the one to try.
It weighs under an ounce and stuffs into an included pull-string sack, so it is as packable as the Sea to Summit net. The drop-neck design extends down over your neck for better coverage, and it fits over a hat or directly on your head with an elasticized crown.
Two small notes. It is a head net only, so your arms and body still need spray or sleeves. And the very fine knit rewards gentle handling, since it is more delicate than a heavy mesh. For clear vision in bug country, it is the standout, and Ben’s also makes a permethrin-treated version if you want the mesh itself to repel bugs on contact.
A barely-there head net that does not block your view
The Original Bug Shirt Elite - Best Full Coverage
When a head net is not enough, because the black flies are biting through your shirt and crawling up your sleeves, you want a bug shirt. The Original Bug Shirt has been made in Ontario since 1991, and the Elite is its top model. It is a hooded shirt that covers you from the top of your head to your waist, with a zippered no-see-um face mesh that you can open to eat, drink, or take a photo without pulling the whole hood off.
The appeal is that it is a pure physical barrier with no chemicals, so there is nothing to wash out, reapply, or worry about against your skin. The fabric also carries a high sun-protection rating, so it does double duty on exposed trails and open paddles. Cinch the hood and waist drawcords and the bugs simply have nowhere to get in.
The tradeoffs are price and heat. It is a premium piece, and because it is a loose layer over your clothes, it can feel baggy and warm in still, hot air with no breeze to move through the mesh. On a buggy trip into a place like Gulf Hagas or out on Moosehead in June, though, total coverage is worth a little extra warmth.
Total bug protection without any chemicals
ExOfficio BugsAway Sol Cool Hoody - Best Treated Clothing
This is the bug protection you can wear all day without looking like a beekeeper. The BugsAway hoody has permethrin, the bug-killing treatment, bound right into the fabric, where it is odorless and invisible and lasts up to 70 washes. Bugs that land on it are repelled or killed on contact, so it works even where the fabric is not a tight barrier.
It is a genuinely good hoody beyond the bug angle. The knit carries a UPF 50 sun rating, it has a cooling fabric that feels good when you are damp with sweat, and an anti-odor finish for multi-day trips. Thumbholes pull the sleeves over the backs of your hands and the hood covers your head, so the coverage extends further than a normal shirt.
Two things to keep in mind. The permethrin is not permanent. It fades after about 70 washes, and then it is just a nice sun hoody, though that is still useful. And it has no face mesh, so for serious black flies you pair it with one of the head nets above. As an everyday treated layer that fights bugs and sun together, it is excellent. For more on treated clothing, see our tick and bug protection guide, which covers sprays and permethrin in depth.
Treated clothing that fights bugs and sun together
Bug Baffler Hooded Mesh Shirt - Best Value Full Coverage
The Bug Baffler is the more affordable way to get full head-and-torso coverage. It is a one-piece hooded mesh shirt, a pure physical barrier with no chemicals, that covers you from your head down through your torso in a single garment. The fine mesh keeps out mosquitoes, black flies, and no-see-ums, and it is made in the USA.
The smart detail is the hood. It is designed with enough room to clear a hat brim, which holds the mesh off your face so you can actually see, the same problem the head nets fight. Soft elastic at the wrists and the hem seals the openings so bugs cannot crawl up underneath, and a front zipper lets you open the face area for a break.
It is all mesh, which is the value-and-comfort tradeoff. That means good airflow but very little sun protection, so it runs warm in direct sun, and the hardware is simpler than the pricier Original Bug Shirt. For a full-body bug barrier at a friendlier price, it covers the essentials well.
An affordable full-body bug barrier
Head Net, Bug Shirt, or Treated Clothing?
These three solve different problems, and a lot of Maine outdoorspeople own more than one. A head net is the minimum: cheap, packable, and the fastest fix when the bugs find your face. It protects only your head and neck, so you pair it with sprayed or covered arms. A bug shirt steps up to cover your whole upper body in mesh, which is the move for the worst conditions and for people the bugs really go after. Treated clothing like the permethrin hoody is the everyday option you wear before the bugs even show up, fighting them and the sun at the same time without a barrier you have to manage.
The combination most Maine regulars land on is a permethrin layer for general wear, a fine-mesh head net in a pocket for when it gets bad, and a full bug shirt for the truly brutal early-June trips. Layer those with the right repellent and you can actually enjoy black fly season instead of fleeing it.
Always wear a brimmed hat under any head net. The mesh has to stay off your skin, because black flies will happily bite through netting that is resting against your forehead or the back of your neck. A ball cap or a wide-brim hat holds the net out an inch or two, which is the whole difference between a net that works and a net that just looks like it should.
For the spray side of bug protection, deet, picaridin, and how to treat your own clothes with permethrin, see our tick and bug protection guide. To plan around the bugs in the first place, the Maine bug season calendar lays out when black flies peak and fade, and the worst black fly trails in Maine flags where you will want all of this gear on.
What to Bring
- A fine, no-see-um grade head net (around 1,000+ holes per square inch), not a standard mosquito net
- A brimmed hat to hold the net off your face
- A bug shirt or treated hoody for the worst early-June trips
- Permethrin-treated clothing or spray for your arms and legs
- A repellent for any exposed skin
- Long sleeves and pants tucked into socks for full coverage
- A backup net, since they are cheap and easy to lose
Why do black flies get through my mosquito net?
Because black flies and no-see-ums are smaller than mosquitoes and slip through ordinary mosquito mesh. A standard mosquito net has roughly 300 to 500 holes per square inch, which stops mosquitoes but not the smaller biters. For Maine black flies you need no-see-um grade mesh, around 1,000 holes per square inch and up. The Sea to Summit Ultra-Fine net at 2,000 is the finest option here.
Do I need a head net for black fly season in Maine?
If you are outside in the woods in late May or June, yes. Black flies peak then and they go for your face, hairline, ears, and the back of your neck, exactly the spots spray misses most. A fine-mesh head net is the most reliable defense for your head, weighs almost nothing, and costs little. Combine it with treated clothing or spray for your arms and legs.
What is the difference between a head net and a bug shirt?
A head net covers only your head and neck, so it is light, cheap, and packable, but you still need to protect your arms and torso another way. A bug shirt is a full hooded garment that wraps your entire upper body in mesh, giving complete coverage for the worst conditions at the cost of more weight and heat. Many people carry a head net for everyday and a bug shirt for brutal early-June trips.
How long does permethrin-treated clothing last?
Factory-treated clothing like the ExOfficio BugsAway hoody is rated to last about 70 washes, after which the bug protection fades and the garment becomes a regular shirt. If you treat your own clothing with a permethrin spray, the protection lasts around 6 weeks or 6 washes per application. Either way, permethrin goes on clothing and gear, never directly on your skin.
Can I just wear a head net without a hat?
You can, but it works much better with a brimmed hat underneath. A head net resting against your skin lets black flies bite right through it, since the mesh has to be held off your face to stop them. A ball cap or wide-brim hat pushes the net out an inch or two, which is the difference between real protection and a net that the bugs ignore.
Is a head net enough, or do I need spray too?
For your face and neck a head net is enough on its own, but it leaves your arms, hands, and legs exposed, so you still want repellent or covered, treated clothing for the rest of you. The most effective setup combines a physical barrier on your head with permethrin-treated clothing and a repellent on any exposed skin. No single method covers everything, especially in peak black fly season.
