How to Stop Midge Bites: Prevention and Treatment

Preventing midge bites comes down to a combination of timing, repellents, and physical barriers, while treating bites that do happen works best with localized heat or mild topical steroids applied quickly. Midges are tiny but remarkably effective biters, and the usual advice for mosquitoes does not always transfer cleanly. The science on what attracts midges, what repels them, and what soothes the itch they leave behind has some genuine surprises worth knowing.

Why Midge Bites Itch So Intensely

When a biting midge lands on your skin, it does not simply pierce and sip like a mosquito. Its mouthparts work by retraction: the mandibles have rear-facing teeth on one edge and essentially saw backward through the skin in a single active cutting stroke.¹ This tearing action creates a small wound pool from which the midge feeds, and it deposits saliva into the wound in the process. That saliva contains proteins that cause swelling, blood-vessel dilation, and itching. In lab tests where midge salivary proteins were injected into human skin, two out of three subjects developed strong itching at the injection site along with visible swelling and redness.²

The reaction people have to these salivary proteins varies. A study of several hundred people exposed to biting midges found that about half experienced an immediate skin reaction, sometimes followed by a delayed reaction, while roughly one in nine had only a delayed reaction that showed up hours later.³ Among those tested further, over half produced specific IgE antibodies against midge proteins, confirming that the itchy welt is a genuine allergic response, not just irritation.³ This is why some people swell dramatically from a single bite while others barely notice: repeated exposure can either sensitize you further or, over long periods, build a degree of tolerance.

When and Where Midges Are Most Active

Timing your outdoor activities is one of the cheapest and most effective ways to avoid bites. Female biting midges (the only sex that bites) follow a predictable daily rhythm, with peak host-seeking activity concentrated at dawn and dusk. One study of the Highland midge, Culicoides impunctatus, found a clear bimodal pattern with a sharp dawn peak between roughly 5:00 and 7:00 a.m. and a second peak around sunset.⁴ Research in the UK using vehicle-mounted traps confirmed that all species examined were caught in greater numbers around sunset, though the strength of this pattern varied by species.⁵

Wind is your best natural ally. Midges are weak fliers, and even a modest breeze disrupts their ability to find you. Research at a southern California dairy found that when wind speeds at sunset were below about 0.69 meters per second (around 1.5 miles per hour, barely perceptible on your skin), peak midge activity hit right at sunset. Higher wind speeds pushed peak activity later, and strong wind suppressed it further.⁶ Humidity, on the other hand, played a surprisingly minor role in regulating flight activity in controlled studies.⁷ The practical takeaway: if you must be outdoors at dawn or dusk, pick an exposed, breezy spot. Sheltered hollows, woodland edges, and calm lakesides are where you will get eaten alive.

Why Some People Get Bitten More Than Others

If you have ever sat in a group outdoors and been the only person covered in bites while everyone else seems fine, you are not imagining it. A large questionnaire-based study found that the vast majority of people (about 86%) reported being bitten at least sometimes when in midge territory, with only around 14% saying they were never bitten.⁸ So almost nobody is truly immune. But who gets bitten most does show patterns.

The study found no link between bite frequency and age, smoking, diet, exercise, medication use, eating strongly flavored foods, or alcohol consumption. That rules out several popular myths in one stroke: garlic does not protect you, and beer does not make you a midge magnet. What did matter was body size. In men, taller individuals were bitten more. In women, higher body mass index was associated with more bites. The researchers also found evidence that susceptibility to midge bites has a hereditary component.⁸

This fits with what we know about how midges find hosts. Like most blood-feeding insects, they rely heavily on smell. Carbon dioxide from your breath is the primary long-range attractant, and a larger body generally produces more of it. Beyond CO2, midges detect specific volatile chemicals from skin and sweat. Research identified several host-derived compounds, including 1-octen-3-ol (a mushroom-scented alcohol found in human and animal skin emissions), phenol, and certain methylphenols, that significantly increased trap catches when combined with CO2.⁹ Intriguingly, some compounds had the opposite effect: octanal and (E)-2-nonenal at certain doses actually repelled midges, drawing significantly fewer to traps than CO2 alone.⁹ Your personal blend of skin chemicals, shaped by genetics and metabolism, determines a lot of your appeal to midges, and there is not much you can do to change it apart from masking it with repellents.

Choosing the Right Repellent

DEET is the default insect repellent most people reach for, and it does work against midges, but the evidence suggests it is not the best option for them specifically. A review of chemical and plant-based repellents found that for anticipated exposure to biting midges (along with sandflies and blackflies), topical products containing IR3535, picaridin, or oil of lemon eucalyptus (the active ingredient is p-menthane-3,8-diol, often listed as PMD) offered better protection than DEET alone.¹⁰ This is a meaningful distinction. Midges are smaller and interact with skin differently than mosquitoes, and the spatial repellency of picaridin and PMD seems to keep midges at a greater distance.

In practice, the choice often comes down to what is available and tolerable on your skin. Picaridin at 20% concentration is widely available, does not dissolve plastics or fabrics the way DEET can, and feels less greasy. PMD (oil of lemon eucalyptus) is the strongest plant-derived option with genuine data behind it, though it needs reapplication more frequently. IR3535 is common in European products and has a good safety profile for children. If you are heading into serious midge country, such as the Scottish Highlands, Scandinavian wetlands, or tropical mangrove areas, combining a topical repellent with permethrin-treated clothing provides the strongest defense.

Physical Barriers and Clothing

Because midges are so small (many species are under 2 millimeters long), standard mosquito netting does not keep them out. You need fine-mesh netting or head nets with a mesh size small enough to block them, typically around 0.5 to 1 millimeter. Head nets designed specifically for midge protection are inexpensive and widely used in places like Scotland and northern Scandinavia. They look a bit silly, but they work.

Clothing color matters more than most people realize. Sticky-trap research on Culicoides midges found that more midges landed on white and clear surfaces than on yellow or blue ones.¹¹ This was a study on cattle, so the context is not a perfect match for human clothing choices, but it does suggest that light-colored clothing may attract more midges to your surface than darker shades. This runs counter to the usual mosquito advice (wear light colors), and it is worth keeping in mind if you are dressing for a midge-heavy environment. Long sleeves and long trousers remain essential regardless of color, since midges will bite any exposed skin they can reach.

Managing Your Surroundings

Midges breed in damp organic matter: wet soil, boggy ground, leaf litter, poorly drained lawns, and similar microhabitats. If you are dealing with midges around your home or a property you manage, habitat modification can make a real difference. Research on landscape design and midge breeding sites found that the choice of ground surface, site drainage, and plant selection all influenced how suitable an area was for midge reproduction. Good paving installation (without cracks or gaps where moisture pools) and proper drainage reduced breeding potential, while the type of ecological ground cover also played a role.¹²

Beyond drainage, a few practical steps help reduce midge numbers around outdoor living areas:

Air movement: Outdoor fans on patios and decks create enough wind to keep midges away. Even a gentle breeze from a box fan is enough to ground them.
Avoid standing water: Empty saucers, blocked gutters, and waterlogged compost bins all provide breeding sites. Midge larvae need consistently moist conditions, so anything you can dry out helps.
Trim dense vegetation: Midges rest in dense, shaded foliage during the day. Thinning shrubs and hedges near seating areas reduces daytime harborage and improves air flow.

CO2-baited traps are sometimes marketed for midge control. The underlying science is sound: midges fly upwind toward CO2 plumes in a dose-dependent way, and adding host-odor chemicals like 1-octen-3-ol to CO2 dramatically increases their attraction.⁹ However, whether backyard traps remove enough midges from a population to noticeably reduce biting is a different question. Traps can monitor populations and reduce numbers in a small area, but midges breed in such vast numbers across wide habitats that trapping alone rarely solves a midge problem. Think of traps as one layer, not a silver bullet.

Treating Bites You Already Have

Once a midge has bitten you, the goal shifts to reducing the itch and swelling before you scratch yourself into a secondary infection. Scratching is the main risk with midge bites: the bites themselves are not dangerous in most parts of the world, but broken skin from scratching can become infected, especially in warm, humid conditions.

Concentrated heat applied to the bite is one of the more effective treatments and is backed by a surprisingly large body of real-world data. A study analyzing over 12,000 treated insect bites (including from various species) found that applying localized heat reduced itch from mosquito bites by about 57% within the first minute and by roughly 81% within five to ten minutes, with overall reductions in both itch and pain that outperformed control groups.¹³ The devices used typically heat a small ceramic tip to around 51°C (about 124°F) and are pressed against the bite for a few seconds. This is thought to denature the proteins in the injected saliva and reduce the inflammatory cascade. Several commercially available devices (often called “bite healers” or “electronic sting relievers”) work on this principle. They are cheap, drug-free, and travel well.

For topical treatments, a mild corticosteroid cream like 1% hydrocortisone is the standard over-the-counter option. A comparative trial of hydrocortisone gel against a herbal alternative for insect bite reactions found that both reduced lesion diameter, itching scores, and redness at each follow-up visit, with no significant difference between the two.¹⁴ Hydrocortisone is widely available and works well for the first day or two of itching. If bites are still inflamed after a few days, or if you see signs of infection (increasing redness, warmth, pus), that warrants a visit to a doctor for possible antibiotics or a stronger prescription steroid.

Oral antihistamines can help if you have many bites and the itching is keeping you awake. A non-drowsy antihistamine like cetirizine taken during the day, or a sedating one like diphenhydramine at bedtime, can take the edge off. Ice or a cold compress applied for ten minutes at a time also numbs the area and reduces swelling. Calamine lotion is an old standby that provides temporary relief through cooling and mild astringent action, though it does not address the underlying allergic mechanism the way hydrocortisone does.

What Does Not Work as Well as People Think

Citronella candles are probably the most common “remedy” people try for outdoor midge prevention, and they are one of the least effective. Citronella oil has some repellent activity, but when burned in a candle the concentration in the air is far too low to create a meaningful barrier, especially against midges that are flying in close to your skin following your CO2 and body-odor plume. You would need to sit in a cloud of smoke dense enough to be unpleasant to breathe for it to matter.

Vitamin B supplements, particularly B1 (thiamine), are another perennial recommendation that has never held up in controlled testing. The idea that B vitamins change your skin chemistry enough to repel insects has been studied repeatedly for mosquitoes and the evidence consistently fails to support it. The questionnaire study on midge biting mentioned earlier found no association between diet and bite frequency.⁸

Ultrasonic repeller devices, which claim to emit a high-frequency sound that drives away biting insects, have been tested in multiple independent studies on mosquitoes and other biters and consistently shown to have no effect. Save your money.

Midges That Carry Disease

In most temperate regions, midge bites are a nuisance, not a health threat. The main exception is in tropical and subtropical areas where certain Culicoides species transmit pathogens. Midges are known vectors of several viruses that primarily affect livestock, including bluetongue virus and Schmallenberg virus. These are economically devastating to farming but do not infect humans. In parts of Central and South America, the Caribbean, and Australia, midges can transmit Oropouche virus, which does cause febrile illness in people, though cases are rarely fatal. A few species in tropical regions also transmit filarial parasites (Mansonella species), which cause a generally mild but chronic infection.

For most readers dealing with midges in Scotland, Scandinavia, Canada, or the northern United States, disease transmission is not a realistic concern. The bites are miserable but medically benign. In tropical settings, particularly if you are near livestock in areas with known bluetongue or Oropouche circulation, the prevention measures above become more urgent for health reasons rather than just comfort.

The Hereditary Component and What It Means for You

The finding that susceptibility to midge bites appears to have a hereditary basis is worth dwelling on for a moment.⁸ If your parents were always the ones getting chewed up on camping trips, you probably will be too, and there is not a dietary trick or supplement that will change it. Your skin’s volatile chemical signature is partly genetic, and midges respond to specific compounds in that signature with remarkable sensitivity. Researchers have identified attractant compounds at doses as low as 0.1 milligrams per hour that significantly increased trap catches over CO2 alone.⁹ The quantities involved are vanishingly small, which is why masking them with a good repellent is more realistic than trying to change them.

This also explains why people who move to midge-heavy areas sometimes feel like they get bitten less after a year or two. It is not that they have become less attractive. Their immune response to the salivary proteins has shifted with repeated exposure, so the welts are smaller and the itch is milder, giving the impression of fewer bites. First-time visitors to the Scottish Highlands or northern Australian coast often react more dramatically to their first season of midge bites than long-term residents do, purely because of immunological sensitization and desensitization patterns rather than any change in how many bites they are receiving.

Building a Layered Defense

No single measure eliminates midge bites entirely, which is why the people who deal with midges most successfully stack multiple strategies. If you are heading into known midge territory, a practical layered approach looks something like this:

Timing: Schedule outdoor activities for midday when midge activity is lowest. Avoid being outside at dawn and dusk if possible.
Location: Choose exposed, breezy spots over sheltered ones. Hilltops and open coastline are better than wooded valleys and still lakeshores.
Repellent: Apply picaridin or PMD-based repellent to all exposed skin. Reapply after swimming or heavy sweating.
Clothing: Wear long sleeves and trousers. Consider permethrin treatment on outer layers. Avoid very light-colored fabrics if midge species in your area respond to pale surfaces.
Head protection: A fine-mesh midge head net for evenings in heavy midge zones.
Site management: If camping, use a fan in your tent vestibule and choose a campsite with good air movement. If at home, improve drainage and reduce standing water.

Carry a localized heat device or hydrocortisone cream for bites that happen despite your precautions. Treating bites within minutes, before the itch-scratch cycle takes hold, gives the best results and prevents the worst of the swelling.

1
PubMed. Anatomy and function of the mouthparts of the biting midge, Culicoides sanguisuga (Diptera: Ceratopogonidae)
2
Journal of Medical Entomology. Collection and Analysis of Salivary Proteins from the Biting Midge Culicoides nubeculosus (Diptera: Ceratopogonidae)
3
PubMed. Hypersensitivity to Forcipomyia taiwana (biting midge): clinical analysis and identification of major For t 1, For t 2 and For t 3 allergens
4
PubMed. Diel flight periodicity of the biting midge Culicoides impunctatus and the effects of meteorological conditions
5
Journal of Medical Entomology. Investigation of Diel Activity of Culicoides Biting Midges (Diptera: Ceratopogonidae) in the United Kingdom by Using a Vehicle-Mounted Trap
6
PubMed Central. Seasonal change and influence of environmental variables on host-seeking activity of the biting midge Culicoides sonorensis at a southern California dairy, USA
7
PubMed Central. The influence of temperature and humidity on the flight activity of Culicoides imicola both under laboratory and field conditions
8
PubMed Central. To bite or not to bite! A questionnaire-based survey assessing why some people are bitten more than others by midges
9
PubMed Central. Evaluation of Host-Derived Volatiles for Trapping Culicoides Biting Midges (Diptera: Ceratopogonidae)
10
PubMed. Chemical and Plant-Based Insect Repellents: Efficacy, Safety, and Toxicity
11
PubMed. Sticky-trapping biting midges (Culicoides spp.) alighting on cattle and sheep: effects of trap colour and evidence for host preference
12
Sustainability. The Effects of Landscape Elements on the Breeding Sites of Bloodsucking Midge
13
PubMed Central. Efficacy of Concentrated Heat for Treatment of Insect Bites: A Real-world Study
14
Journal of Cosmetics, Dermatological Sciences and Applications. Comparative Study of Herbal Extracted Gel and 1% Hydrocortisone Gel in the Treatment of Mosquito Bite Reaction