Yes, no-see-ums bite, and the itch they leave tends to be stronger than their tiny size would suggest. Only the females bite, and they do it to get the blood they need to make eggs.1EDIS. Bluetongue The real culprit behind the misery is how your own skin reacts to what the insect leaves behind, which is also why some people suffer far more than others.
How a No-See-Um Bite Actually Works
No-see-ums are biting midges, flies so small that most people never see the one biting them. In most species the female feeds on the blood of people or animals to get nutrients for developing her eggs.2EDIS. Biting Midges, No-See-Ums Culicoides spp. Insecta Diptera Ceratopogonidae A few species can lay a first batch of eggs without any blood meal.3EDIS. Biting Midges, No-See-Ums Culicoides spp. Insecta Diptera Ceratopogonidae
The midge is often smaller than a pinhead and lands without a sound. You may feel a sharp, pinprick-like sting at the moment it feeds, but by the time you look, it is usually gone. Many people feel nothing at all, and the first sign is itching hours later.
Unlike a mosquito, which slides a fine tube into a blood vessel, a no-see-um’s mouthparts tear through the outer skin.4Longsleeve. Why No-See-Um Bites Itch So Much, and How to Treat Them This does real damage to the layer beneath, and blood collects in a tiny pool that the midge drinks from.5Longsleeve. Why No-See-Um Bites Itch So Much, and How to Treat Them Its saliva contains substances that stop blood from clotting.6PubMed. Collection and Analysis of Salivary Proteins from the Biting Midge Culicoides nubeculosus (Diptera: Ceratopogonidae) A torn wound with saliva sitting in it gives the body more to react to than a neat puncture would.
The saliva is what starts the itch. When no-see-um saliva alone was injected into human skin, it caused swelling, flushed skin and itching.7PubMed. Collection and Analysis of Salivary Proteins from the Biting Midge Culicoides nubeculosus (Diptera: Ceratopogonidae) It also sets off skin cells that release histamine, the body chemical behind itch and redness.8PubMed Central. The use of concentrated heat after insect bites/stings as an alternative to reduce swelling, pain, and pruritus: an open cohort-study at German beaches and bathing-lakes
The itch usually grows after the bite as the immune system responds to the saliva left in the skin, so bumps can appear or itch hardest hours after you have gone indoors. People who have been bitten many times may react more mildly over time, while someone newly exposed, such as a traveler at a coastal resort, can react strongly.
What No-See-Um Bites Look Like and How Long They Last
No-see-um bites show up as small red dots, often grouped in clusters.9Insect Shield. Do No See Ums Bite? Symptoms and Relief Unlike a mosquito bite, there is usually no visible puncture mark at the center.10Insect Shield. Do No See Ums Bite? Symptoms and Relief The dots can swell into raised, itchy welts.11Insect Shield. Do No See Ums Bite? Symptoms and Relief Some people’s reactions also include small fluid-filled blisters and swelling around the bites.12PubMed. Papular urticaria and things that bite in the night
Mosquito bites are usually larger, slightly raised and appear one at a time.13J.C. Ehrlich. Mosquito vs. no-see-ums: What’s the difference? No-see-um bites are much smaller, come in clusters and often itch more intensely.14J.C. Ehrlich. Mosquito vs. no-see-ums: What’s the difference?
Exposed skin takes the brunt: ankles, wrists, neck, face and hairline are typical spots. Clusters along the edge of clothing are common because midges crawl to bare skin.
How bad the bites get depends on how your immune system reacts to the saliva.15Cutis. Dermoscopic Documentation of a No-see-um Bite Doctors call a strong itchy-bump reaction to bites from midges and similar insects papular urticaria, and it is very common.16PubMed. Papular urticaria and things that bite in the night
The itch usually peaks within the first day as the skin reaction builds. Most bumps fade over several days to a week without treatment. Scratching keeps them inflamed and can make them last longer.
Other biters can leave groups of itchy bumps too, so the setting is the best clue. Bites after an evening near water or marsh fit no-see-ums. Chigger bites also come in groups and itch intensely, but they cluster where clothing fits tightly, such as sock lines and waistbands, after contact with grass or brush. Flea bites most often land on the ankles and lower legs, usually after contact with pets or infested carpet. Bed bug bites tend to show up on skin exposed during sleep, and new ones keep appearing while you sleep in the same place.
Fastest Ways to Stop the Itch
Applying brief, concentrated heat to a bite can cut itching quickly.17PubMed Central. Efficacy of Concentrated Heat for Treatment of Insect Bites: A Real-world Study For mosquito bites, heat reduced itch by about half within a minute and by about four-fifths within 5 to 10 minutes.18PubMed Central. Efficacy of Concentrated Heat for Treatment of Insect Bites: A Real-world Study Heat also eased swelling and pain from bites at beaches and lakes, including midge bites.19PubMed Central. The use of concentrated heat after insect bites/stings as an alternative to reduce swelling, pain, and pruritus: an open cohort-study at German beaches and bathing-lakes It appears to switch on nerve sensors that override the itch signal the midge saliva triggers.20PubMed Central. The use of concentrated heat after insect bites/stings as an alternative to reduce swelling, pain, and pruritus: an open cohort-study at German beaches and bathing-lakes
Handheld bite-relief devices press a small ceramic tip, warmed by a battery, against the bite for a few seconds, and they are designed to stay within a safe temperature. A homemade version is a spoon warmed in hot tap water, dried off and tested on your inner wrist before it touches the bite. The heat should feel warm, never painful. Treat each bump separately, since the heat only reaches the spot it touches.
Skip heat on broken, scratched or infected skin, where it could sting and make things worse. Avoid it on young children who cannot tell you when it is too hot. If the swelling is already large, heat may not do much, and a cool compress is a gentler choice.
Hydrocortisone, a mild steroid cream, is sold without a prescription in 0.5% and 1% strengths.21Journal of Integrative Dermatology. Beyond the Prescription Pad: A Guide to Over-the-Counter Itch Management It is commonly used to calm itching from insect bites.22Journal of Integrative Dermatology. Beyond the Prescription Pad: A Guide to Over-the-Counter Itch Management Apply a thin layer a few times a day. The 1% strength is stronger, and most adults use it for intense itch. Avoid it on broken skin, and don’t use it for many weeks without advice.
A paste of baking soda and water is a popular home remedy to soothe itchy, inflamed skin, but it is supported only by anecdotal experience, not testing.23Best Bee Brothers, LLC. No-See-Um Bites Treatment A few other steps help. Washing the area with soap and water is a sensible first move. Cool compresses, or ice wrapped in cloth, numb the itch and reduce swelling. If itching keeps you awake, an oral antihistamine at bedtime can help.
When a Bite Becomes a Problem
Scratching breaks the skin’s surface and lets germs in, so scratched bites can become infected.24Cutis. Dermoscopic Documentation of a No-see-um Bite25Mosquito Squad. What is the Fastest Way to Heal No-See-Um Bites? Keeping nails short and covering bites at night helps.
Redness that spreads outward from the bite, along with warmth and a hard, swollen area, suggests bacteria are multiplying in the skin. Pus or honey-colored crusting on the surface is a classic sign of infection. Pain that grows after a couple of days is the opposite of a normal bite, which should slowly improve. Fever or red streaks running from the bite mean the infection may be spreading, so see a doctor promptly.
Disease risk depends on where you are. Biting midges can carry Oropouche virus and parasitic worms that affect people, mainly in South America and Africa.26EDIS. Biting Midges, No-See-Ums Culicoides spp. (Insecta: Diptera: Ceratopogonidae) Oropouche usually causes fever, severe headache, chills and muscle and joint aches.27New York State Department of Health. Oropouche Virus Fewer than 1 in 20 people develop more serious illness, and most recover within days to a month.28New York State Department of Health. Oropouche Virus
For a traveler, the concern applies to people who have recently been in affected areas such as the Amazon region or the Caribbean. Fever and a severe headache within about two weeks of returning are reason to see a doctor. Tell the doctor about the bites and exactly where you traveled, since that history guides which tests make sense. Ordinary North American backyard bites don’t carry this concern.
True allergic reactions are rare. Swelling of the face or lips, hives far from the bites, or trouble breathing is an emergency. Large swollen areas around clusters are uncomfortable but usually not dangerous.
Where and When No-See-Ums Bite
Most no-see-ums bite around sunrise and sunset.29BuzzSkito. No-See-Ums: What They Are and How to Stop Them In cool weather and in coastal areas, many bite in broad daylight.30BuzzSkito. No-See-Ums: What They Are and How to Stop Them They are more active on overcast, humid days.31Bug-N-A-Rug Exterminators. Do No See Ums Bite? Symptoms and Relief Even a slight breeze stops most feeding, because they are too small to fly well in wind.32BuzzSkito. No-See-Ums: What They Are and How to Stop Them
They breed in damp spots rich in rotting plant matter, such as marsh edges, shorelines and poorly drained ground.33Mosquito Shield. No-See-Ums They are most abundant in summer, peaking in June through August in places like Florida.34BuzzSkito. No-See-Ums: What They Are and How to Stop Them Where winters are warm they can bite year-round.35BuzzSkito. No-See-Ums: What They Are and How to Stop Them In fall and winter they are practically absent from states north of Missouri.36Best Bee Brothers, LLC. No-See-Um Seasonality Range Map & Season Information
Biting midges find hosts partly by the carbon dioxide in exhaled breath, so people breathing hard from exertion give off a stronger signal. Body heat and the odor of sweat also draw them in, which makes yard work or a brisk walk at dusk a risky time. Dark clothing may hold more heat and draw more midges, though that is one factor among several. Because everyone gives off these signals, being bitten more often is not a sign that something is wrong with you.
Soggy lawn patches, boggy corners and piles of rotting leaves can all host larvae. Improving drainage and clearing wet debris can cut local numbers over time, though it won’t remove midges that drift in from nearby marsh or shoreline.
How to Avoid Getting Bitten Again
DEET works well against biting midges as well as mosquitoes.37Extension. Insect Repellents Picaridin also works well against no-see-ums.38Extension. Insect Repellents Apply either to all exposed skin, including the ankles, wrists, neck and hairline, since midges find any gap. Put it on before the evening outing begins, and reapply as the label directs, especially after sweating or swimming. Sunscreen goes on first and repellent over it, so each can work as intended.
Strongly scented lotions, perfumes and shampoos may draw no-see-ums.39Mosquito Squad. What Attracts No-See-Ums? Choose unscented products before outdoor time. Outdoor lights can attract them too.40Mosquito Joe. What Attracts No-see-Ums to an Area and How to Repel Them Since wind grounds them, a fan on a porch or patio can keep them off.
Ordinary window screens have holes large enough for no-see-ums to pass through. Look for mesh sold as no-see-um screen or netting, which has much smaller openings. Finer mesh restricts airflow, so a fan helps keep air moving through the space.
Clothing helps as well. Light-colored long sleeves and long pants reduce bare skin, and near marshes it pays to tuck pants into socks, since midges crawl to skin. Repellent-treated clothing adds protection. Schedule yard work or walks away from dawn and dusk on still days.