Biting midges, commonly called no-see-ums, are a persistent warm-weather pest across much of Michigan, especially in lakeside and wetland communities. These tiny flies (roughly 1 to 3 millimeters long) are small enough to pass through standard window screens, and their bites can cause reactions ranging from mild itching to painful, swollen welts that last for weeks. Here’s what Michigan residents and visitors need to know about when they show up, how to deal with bites, and why these insects matter beyond just being a nuisance.
Where and When They’re Most Active
Biting midges thrive wherever there’s standing water, damp soil, and humidity. In Michigan, that means lakeshores, wetlands, marshes, and wooded areas near rivers are prime habitat. Waterfront communities like Muskegon deal with especially heavy populations because the lakes keep humidity high and soil moist even during drier stretches of summer. Inland areas generally see fewer midges, though any property near a pond, creek, or marshy low spot can have them.
The insects are most active from late spring through early fall, with peak biting concentrated around dawn and dusk. They remain present throughout the warmer months as long as conditions stay humid. Activity drops sharply with the first hard frost, which kills adult midges. In Michigan’s Lower Peninsula, that typically means relief arrives sometime in October, while northern counties may see midges taper off a bit earlier as temperatures cool.
What Bites Feel and Look Like
Despite their tiny size, biting midges pack a disproportionately irritating bite. The initial bite is often painful, a sharp pinch that seems impossible from something so small. For some people, though, the itching doesn’t start for several hours, so you may not realize you’ve been bitten until well after you’ve gone inside.
The severity of the reaction varies widely. People who live in midge-heavy areas year-round often become desensitized over time, eventually noticing only mild redness or no reaction at all. Visitors, seasonal residents, and anyone without regular exposure tend to have it worse. Bites can swell to several centimeters across, form blisters, become weepy, and persist for days or even weeks. Because midges feed in swarms, you rarely get just one bite, which compounds the misery.
Treating Midge Bites
Most midge bites can be managed at home. For quick itch relief, look for over-the-counter topical products containing camphor and menthol or pramoxine (a mild numbing agent), which can be applied several times a day. If the itching lingers, a hydrocortisone cream applied once daily helps bring down inflammation. Resist the urge to scratch. Broken skin from scratching is the main way midge bites become infected, and infected bites are the reason a minor annoyance can turn into a real problem.
Cold compresses also help reduce swelling in the first few hours. If you develop bites that blister, keep them clean and covered. Widespread swelling, increasing redness, or warmth spreading outward from a bite can signal infection and warrants medical attention.
Repellents That Actually Work
Not every insect repellent is equally effective against midges. DEET remains the gold standard. It works well on biting midges, mosquitoes, and black flies. Products with up to 30% DEET provide the longest protection, though lower concentrations still work for shorter outings. Picaridin is another strong option, effective against midges and chiggers in addition to mosquitoes.
Oil of lemon eucalyptus (sometimes listed as PMD on the label) is the most common plant-based alternative, and products containing it do list no-see-ums on the label. The catch is that it needs to be reapplied far more frequently than DEET, and testing has shown it performs well only in the first few minutes after application before effectiveness drops off. If you prefer a natural repellent, plan on reapplying often.
IR3535, the active ingredient in several Avon products, is also registered for biting midges and no-see-ums, offering another option for people who want to avoid DEET.
Keeping Midges Out of Your Home
Standard window screens use a 14×18 mesh, meaning 14 strands per inch in one direction and 18 in the other. Biting midges are small enough to fly right through those openings. If midges are getting inside your home, cabin, or screened porch, you need a finer mesh. A 20×20 no-see-um screen has tighter weave that blocks the smallest biting flies while still allowing reasonable airflow. These screens are widely available and install the same way as standard screening. The tradeoff is slightly reduced ventilation and visibility, but for lakefront properties in heavy midge territory, it’s one of the most effective long-term fixes.
Fans also help. Midges are weak fliers, and even a moderate breeze from a box fan or ceiling fan on a porch can keep them from landing on you.
The Bigger Problem: Disease in Michigan Deer
Biting midges aren’t just a nuisance for people. In Michigan, they’re the primary vector for epizootic hemorrhagic disease (EHD), a viral illness that kills white-tailed deer. The disease spreads when midges of the species Culicoides variipennis bite an infected deer and then bite a healthy one. Deer can’t catch EHD from each other directly.
EHD hits fast. Deer develop symptoms about seven days after being bitten by an infected midge. They stop eating, lose their fear of humans, salivate excessively, and grow progressively weaker. Within 8 to 36 hours of showing visible signs, most affected deer go into shock and die. The mortality rate is high enough that a single outbreak can drastically reduce the deer population in a local area.
Every documented Michigan outbreak has occurred between August and October, and outbreaks end within about two weeks of the first frost, when cold weather kills the midges. Recent years have seen die-offs across numerous counties in southern and central Michigan, including Allegan, Berrien, Calhoun, Jackson, Kalamazoo, Kent, Washtenaw, Ingham, and many others. Hunters and landowners who find dead deer near water sources in late summer should report them to the Michigan Department of Natural Resources, as this is a hallmark sign of EHD.
EHD does not infect humans. You cannot get the virus from a midge bite or from handling infected deer. The concern is purely ecological and affects deer herd management and hunting prospects in affected areas.