Bugs of the Upper Peninsula

Between the months of April and October a plague of insects descends upon the Upper Peninsula of Michigan. A variety of biting and blood-sucking bugs, flying and crawling, lie in wait in the woods for unsuspecting visitors to lash out. Swamps, rivers, hills, beaches: no place is safe. Rumor has it that 2014 is one of the worst years, though the same rumor circulated about 2013 (and even 2012 was pretty bad).

Over the course of my hikes in the UP I've dealt with all types of biting insects and have worked out a few strategies to avoid them. Typical blockers, like DEET bug spray, does little to hold them back. You need to get creative. Some bugs will bite through clothes while others will aim for specific areas of skin. Here's a breakdown of the bugs to watch out for.

Deer Fly

Deer Fly

Deer Fly, photo by Bruce Marlin

Also known as Cutter Flies, these things are some of the most annoying creatures that you'll run into in the northwoods. They are fast, usually buzzing around in tight circles around your head, though they land silently and take a bite out before you notice. Their bites hurt, not itch, and may swell into a painful bump that can last days (depending on the location). Oh, and they are tougher than a normal fly and may last through a half-hearted swat.

Deer Flies have a relatively long season, stretching from late May through September, and can be found in thick forests. A good wind will keep them back, so hiking along bluffs or a breezy shoreline will deter them. Otherwise covering up seems to be a good option. They are attracted to exposed skin and hair, so as long as you wear a hat (and maybe a bug net) and long-sleeves only their incessant buzzing will be an annoyance.

Black Fly

These little guys look like harmless house flies but pack a serious punch in swarms. Better known as Stable Flies (or Sable Flies in the Grand Marias area) they tend to keep to farm animals, piling upon their ankles and slicing small cuts to drink blood from. Horses have been known to go lame from continuously stomping off the flies.

Black Flies also stick around for a long time, from June through September, though they are not as resilient as Deer Flies are to temperature swings. Their spread through the woods is sparse, making them a minor threat, until the 'south wind' phenomenon shows up. A southern wind will shove all of the flies north to the shoreline where they swarm on hapless Lake Superior beachgoers.

The best defense is thick clothes. They will bite through some fabrics, especially lighter colors, so the old 'tuck pants in socks' trick for ticks make an appealing target for them. Jeans, jean jacket, and maybe even gloves will keep them from biting. Their bites do not hurt for long, more sharp needle stings that quickly fade, but when you're stuck in the middle of hundreds of Black Flies slicing you dozens of times per minute it doesn't take long for them to get to you.

Horse Fly

Rare and gargantuan, these flies are like tanks of the woods. I've only seen a handful of them, mostly in thick woods during the month of July. They hurt, though. They will bite through anything and leave a very painful welt that makes Deer Flies seem like mosquitoes. They are also surpringly quiet for their size, able to find you, land, bite, and take off before the pain sets in. There is no good way to avoid these things outside of wearing plate armor.



Mosquito, photo by JJ Harrison

Of course, there is the Mosquito, the state bird of Michigan. They have a long season that lasts most of summer. They are susceptible to harsh weather, though, and a good cold stretch will give several days of respite. Mosquitoes tend to favor wet areas more, swampy land for easy breeding, and will come out in greater numbers before/after rain and during sunrise and sunet.

Bug spray does help against them, though I haven't been able to find a spray that is effective for longer than an hour. The best defense is just to keep covered. Thick clothes, bug nets, gloves - whatever it takes to keep their proboscises out of skin. Their bites are annoying but, if you can avoid itching, may fade after twenty minutes.


One insect with a shorter season is the Gnat. They only last in early spring, waking up during the melt and sticking around for maybe a month. Small, whiny, and without much bite, they often escape most people's notice.

When a Gnat bites it will usually go for protected, sweaty areas: behind the ear, under the brim of a hat, etc. They will usually crawl around after landing, which may give away their location, allowing ample time for preventive measures to be taken. Where they really get annoying is when they aim for the ears and nose looking for moisture. A small swarm of tiny Gnats biting your forehead and crawling into your eyes can be just as maddening as the more prevalent Mosquitoes.


Black-Legged Tick

Black-Legged Tick, photo by Jim Gathany

There are bugs that don't fly that are also a nuisance. Ticks come out in the early summer and crawl around on foliage looking for passing animals to latch on to. After grabbing on they'll crawl around, looking for a way past clothes, and after finding some good skin will hold and bite deep, sinking their head in to get a good grip.

Ticks are one of the few bugs that also carry disease. Lyme Disease has been slowly spreading across the Midwest, and while there are no reported cases in the UP that I've heard of, is still something to watch for. Sure, Mosquitoes can also carry things like West Nile, but I don't think that's as much of a concern so far north.

There are several good ways to work with Ticks. Pants-tucked-in-socks is a good look that happens to block them from crawling up your legs. Also, tucking in your shirt. A few may find a way in or, if they are ambitious, may get up to your hair and/or drop down the back of a shirt. A good tick-check is helpful to make, both when getting back in the car after a good hike (they may still grab onto your clothes in hopes of getting a free ride) and when settling down for the night in a tent/house. Their bites are not too bad, mild itching at best, though you don't want to leave a tick embedded in you for longer than you can help it.

These six bugs are the main ones I've dealt with while hiking. There's more up there to watch out for - I've run into yellow jackets, wasps, spiders, and more - but these six are by far the most widespread. They are annoying, sure, but they are only around in the summer, which makes winter (and fall) excursions that much more appealing. Plus, they keep the woods fairly free of other hikers in the lush summer.