The Primary Attractants: How No-See-Ums Find You
For humans and other warm-blooded hosts, no-see-ums rely on several key cues to find their next meal. Only the females bite, as they require a blood meal to produce eggs, much like mosquitoes. Understanding these signals is the first step in effective prevention.
Carbon Dioxide (CO2) and Lactic Acid
As mammals breathe and perspire, they emit a plume of carbon dioxide and lactic acid. These chemical signals are extremely potent attractants for biting insects like no-see-ums, which can detect them from a surprising distance. Heavier breathing, such as during exercise, can increase your CO2 emissions and make you a more noticeable target.
Body Heat and Odor
No-see-ums have a keen sense for body heat, using it to pinpoint a potential host. Furthermore, our unique blend of body odors, amplified by sweat and perspiration, acts as an additional lure. Everyone's specific scent profile is different, which may explain why some individuals seem to attract more bites than others.
Dark Clothing
Research suggests that dark-colored clothing absorbs more heat, making a person wearing such attire more appealing to no-see-ums. Opting for light-colored, loose-fitting clothing can help reduce your attractiveness to these pests, and also provides a protective layer against bites.
Floral Scents
Beyond human body cues, certain floral or fruity scents can also attract no-see-ums. Heavily scented lotions, perfumes, and even some shampoos can mimic these aromas, drawing the insects closer. It is best to avoid using such products when venturing into areas known to have no-see-um activity.
Habitat Attractants: Where No-See-Ums Thrive
While personal attractants draw them to you, specific environmental conditions are necessary for no-see-ums to breed and thrive. These are the locations you should be most cautious around.
Standing Water and Moist Soil
Like mosquitoes, no-see-ums lay their eggs in damp environments. This includes areas with standing water, moist soil, marshes, and the edges of ponds or streams. Eliminating stagnant water around your property is a critical step in controlling their population.
Decaying Organic Matter
No-see-um larvae feed on small organisms found in decaying organic matter, such as mud, decaying leaves, and manure. Coastal areas with decaying seaweed or other washed-up vegetation provide an ideal breeding habitat.
Dense Vegetation
Overgrown shrubs, tall grass, and unkempt foliage offer sheltered, moisture-rich areas where no-see-ums can hide and breed. Keeping your yard tidy and landscaping maintained can help reduce their numbers.
Timing and Traps: Activity Patterns and Lures
No-see-um activity is not constant. Their behavior is influenced by the time of day and certain artificial lures.
Dawn, Dusk, and Calm Weather
No-see-ums are most active during low-light periods, specifically at dawn and dusk. They also dislike strong winds, so you are most vulnerable on calm, overcast days. If possible, avoid being outdoors during these peak times, especially near water sources.
Light Sources
Many types of insects, including no-see-ums, are drawn to light. Leaving porch lights on at night can act as a beacon, attracting them to your home. Using yellow, low-wattage 'bug lights' or keeping curtains closed can help reduce this attraction. Specialized CO2 and UV light traps are also commercially available to lure and capture these pests.
Prevention Strategies and Repellents
While understanding what attracts no-see-ums is key, a multi-pronged prevention strategy is most effective for minimizing bites.
- Use EPA-Registered Repellents: Apply an insect repellent containing DEET, picaridin, or oil of lemon eucalyptus to exposed skin. These are proven to be effective against biting midges.
- Wear Protective Clothing: Choose light-colored, loose-fitting, long-sleeved shirts, pants, and socks to reduce skin exposure. No-see-ums can bite through tight-fitting clothing.
- Install Fine-Mesh Screens: Standard window and door screens often have holes large enough for no-see-ums to pass through. Replace them with fine-mesh screens (20x20 mesh or smaller) to create a barrier.
- Eliminate Breeding Sites: Regularly check for and remove sources of standing water, including potted plants, bird baths, and clogged gutters. This is crucial for long-term control.
- Use Fans Outdoors: Since no-see-ums are weak flyers, using a fan on your porch or patio can help create an air current that keeps them away from your seating area.
- Avoid Peak Hours: Limit your time outdoors during dawn and dusk, especially in high-risk areas like marshes or wetlands, when no-see-um activity is highest.
Comparison of No-See-Um Attractants
| Attractant | Source | Primary Mechanism | Prevention Strategy |
|---|---|---|---|
| Carbon Dioxide | Exhaled breath | Chemical signal | Avoid strenuous activity outdoors during peak hours. |
| Lactic Acid | Human sweat | Chemical signal | Bathe after exercise; use effective repellents. |
| Body Heat | Body warmth | Thermal signal | Wear light-colored clothing; use fans. |
| Floral Scents | Perfumes, lotions | Chemical odor | Avoid scented products when outside. |
| Moisture | Standing water, damp soil | Environmental | Eliminate standing water; improve drainage. |
| Decaying Matter | Organic debris | Environmental | Keep yard tidy; cover compost bins. |
| Light | Outdoor lighting, windows | Visual signal | Turn off outdoor lights; use yellow 'bug lights'. |
Conclusion: Minimizing Your Attraction
No-see-ums are attracted by a combination of human-specific cues and environmental factors. By being mindful of your behavior and surroundings, you can significantly reduce your risk of being bitten. While you can't eliminate your natural emissions of CO2 or body heat, controlling other factors like your choice of clothing, scented products, and the state of your immediate environment can make a world of difference. For the most effective protection, remember to combine personal repellents with environmental modifications. For more information on insect-borne viruses potentially carried by biting midges, consult the CDC recommendations.
