Mosquitoes and Blood Type: Does Your Blood Type Attract Mosquitoes?

Mosquitoes and Blood Type: What the Research Shows

If you seem to get bitten more than the people around you, your blood type might be part of the explanation. Research suggests that mosquitoes do show preferences for certain blood types, though the picture is more complex than viral social media posts would have you believe.

The Key Study

The most frequently cited research on this topic was published in the Journal of Medical Entomology in 2004. Researchers examined the landing preferences of Aedes albopictus mosquitoes and found:

• Mosquitoes landed on Type O individuals approximately 83 percent of the time
• Mosquitoes landed on Type A individuals approximately 47 percent of the time
• Type B individuals fell between the two groups

This suggests a roughly two-to-one preference for Type O blood over Type A. However, this was a single study with a limited sample size, and the results have not been consistently replicated across all mosquito species.

The Secretor Factor

An important nuance is the concept of "secretor status." Approximately 80 percent of people secrete blood-type antigens (chemical markers associated with their ABO blood type) through their skin and other body fluids. The remaining 20 percent are non-secretors.

Research indicates that mosquitoes show stronger blood-type preferences among secretors, presumably because the blood-type markers are detectable on the skin surface. Non-secretors of all blood types are bitten at more similar rates.

Blood Type in Context

While blood type may influence mosquito attraction, it is just one factor among many. Other factors that affect how attractive you are to mosquitoes include:

• CO2 output: A stronger attractant than blood type signals
• Skin bacteria: The microbial community on your skin produces volatile compounds that strongly influence bite rates
• Body heat and sweat: Exercise, metabolism, and body size all affect these cues
• Genetics: Twin studies suggest that 85 percent of the variation in mosquito attractiveness is heritable, with blood type being just one genetic component

For a complete list of factors, see our guide on what attracts mosquitoes.

Can You Change Your Attractiveness?

You cannot change your blood type, but you can mitigate the other factors that make you attractive to mosquitoes:

• Use EPA-registered repellent to mask the chemical signals mosquitoes follow
• Shower after exercise to reduce sweat, lactic acid, and body heat
• Wear light-colored, loose-fitting clothing
• Use fans in outdoor areas to disperse attractant plumes
• Time outdoor activities to avoid peak biting hours

The Bottom Line

Yes, blood type likely plays some role in how attractive you are to certain mosquito species, with Type O appearing to be slightly more preferred. However, blood type alone does not determine your overall bite risk. The CO2 you exhale, the bacteria on your skin, your body temperature, and your sweat composition all matter more in combination.

Regardless of your blood type, consistent use of repellent and elimination of breeding sites around your home are the most effective ways to reduce bites. For a comprehensive approach, visit the complete guide to mosquitoes.

Other Blood-Related Factors

Beyond ABO blood type, other blood-related characteristics may influence mosquito attraction:

Rh Factor

Some preliminary research suggests that Rh-positive individuals may attract slightly more mosquitoes than Rh-negative individuals, but the evidence is not strong enough to draw definitive conclusions.

Blood Chemistry

The chemical composition of your blood, including levels of uric acid, lactic acid, and other metabolites, is influenced by diet, exercise, and genetics. These compounds can reach the skin surface through sweat and may affect how attractive you are to mosquitoes, independent of blood type.

Immune Status

People with certain immune conditions may produce different volatile organic compound profiles on their skin, potentially altering their attractiveness to mosquitoes. This area of research is still in its early stages.

What the Research Means for You

If you have Type O blood, you may face a slightly higher baseline mosquito attraction. However, this does not mean you are helpless. The practical implications are:

1. Be more diligent with repellent: If you know you tend to attract more bites, make repellent application a non-negotiable habit before going outdoors
2. Focus on controllable factors: You cannot change your blood type, but you can change your clothing color, reduce exercise-related sweat before outdoor events, and use fans to disrupt mosquito approach
3. Do not blame it all on blood type: Even within the same blood type, there is enormous variation in bite rates due to skin bacteria, metabolic rate, and other factors
4. Protect the whole family: Every household member should follow prevention tips regardless of blood type, since no blood type is immune to mosquito bites

The Bigger Picture of Mosquito Attraction

Blood type is a fascinating piece of the mosquito attraction puzzle, but it is far from the whole picture. If you want to genuinely reduce your bite rate, focus on the factors you can control: consistent repellent use, appropriate clothing, source reduction, and timing of outdoor activities. These interventions will have a far greater impact than anything related to your blood type.

For a deeper dive into all the factors that draw mosquitoes to certain people, read our guide on what attracts mosquitoes.

Expert Observations

The question of blood type and mosquito preference comes up at nearly every community presentation I give. While there is some research suggesting Type O blood may attract Aedes aegypti at slightly higher rates, I always tell audiences that CO2 output, body heat, skin bacteria, and sweat composition are far more important factors in real-world conditions. During outdoor field observations across the Southeast, I have seen heavily-bitten individuals across all blood types. The best approach is consistent repellent use regardless of your blood type. — Sarah Mitchell, BCE

Citations and Further Reading

• CDC – What Attracts Mosquitoes – CDC information on factors that influence mosquito host selection.
• WHO – Mosquito Host-Seeking Behavior – WHO research summaries on mosquito sensory biology and attraction cues.
• American Mosquito Control Association – Mosquito Attraction – AMCA educational resources on the science of mosquito host preference.
• University of Florida – Mosquito Host Selection – Entomological research on factors influencing why mosquitoes prefer certain hosts.

How to Identify

If you experience significantly more mosquito bites than others in the same outdoor setting, blood type may be a contributing factor, but several more powerful attractants should be considered first. Carbon dioxide output (driven by body size and metabolic rate), body heat, lactic acid and other skin volatiles, exercise-induced metabolic byproducts, dark clothing color, and skin microbiome composition are all documented attractants with stronger and more consistent evidence bases than blood type. If you are a heavier or larger person, more physically active, wearing dark-colored clothing, or recently exercised before outdoor exposure, these factors dominate the attraction profile. Blood type's role is statistically real in published research but modest in magnitude relative to these other variables. Ruling out more powerful attractants before concluding that blood type is the primary driver of your bite frequency is the correct diagnostic sequence.

Risk and Severity

Blood type does not affect the severity or outcome of a mosquito bite or mosquito-transmitted disease. Once a mosquito bites, disease transmission risk is determined by whether the mosquito is an infected vector for the local pathogen--not by the host's blood type. Individuals who receive more bites due to any attractant combination are exposed to more transmission opportunities, which cumulatively increases risk in a disease-active area. This is the primary practical significance of heightened attractiveness: more bites means more exposure events, each carrying its own transmission probability. For individuals who are genuinely higher-bite-frequency people regardless of blood type, consistent repellent use and source reduction carry proportionally more protective value than they do for lower-frequency individuals.

Solutions and Actions

No practical intervention changes blood type, and the evidence does not support commercial products that claim to mask blood type-based attractant signals. The most effective response to higher-than-average bite frequency--regardless of cause--is consistent use of EPA-registered repellents. Apply DEET (20-30%) or picaridin to all exposed skin before outdoor activities; these repellents mask CO2 and volatile attractant signals that mosquitoes use to locate hosts, covering the attractant cues that matter most. Wear light-colored clothing; dark colors attract mosquitoes visually and absorb heat, increasing temperature-based attraction. Shower before outdoor activities to wash off lactic acid and metabolic byproducts from physical activity. Treat clothing with 0.5% permethrin. These measures address the controllable attractant variables more reliably than any blood-type-specific intervention.

Prevention

Consistent protective behaviors reduce bite frequency regardless of blood type. Apply EPA-registered repellent to all exposed skin before any outdoor activity during mosquito season. Treat clothing and gear with 0.5% permethrin before the season starts. Schedule outdoor activities outside peak Aedes (daytime) and Culex (dusk-to-dawn) biting windows where practical. Wear long sleeves and light-colored pants during high-exposure situations. Eliminate standing water weekly within 100 feet of your home to reduce the source population. Keep window and door screens intact. If you have historically been a higher-bite-frequency individual, regard repellent application as non-negotiable in disease-endemic areas during transmission season; the cumulative benefit of consistent protection is greater for someone who would otherwise receive a large number of bites.

Main Causes

Yard and indoor mosquitoes activity is driven entirely by accessible standing water for larval development. Even small volumes — water in clogged gutters, plant saucers, birdbaths not refreshed weekly, tarps holding rain pools, unused tires, toy buckets, corrugated downspout extensions, and pet bowls — produce hundreds to thousands of adults per container per week. Adults rest in shaded vegetation during the day and emerge at dawn and dusk to seek hosts. They enter homes through torn screens, gaps around doors, and any time exterior doors are propped open in warm weather. Properties next to wetlands, drainage ditches, and shaded woodlots face higher baseline pressure even with clean yards.

Frequently Asked Questions

Do mosquitoes really prefer certain blood types?

Some studies, particularly a 2004 study on Aedes albopictus, found that Type O blood may attract slightly more mosquitoes than other blood types. However, the research is limited, and the effect is small compared to other attractants like CO2 output, body heat, and skin chemistry. Blood type alone does not determine how much you get bitten.

Does Type O blood explain why mosquitoes seem to prefer me?

Type O blood may be one factor, but it does not explain mosquito attraction by itself. Carbon dioxide output, body heat, sweat chemistry, clothing color, pregnancy, alcohol, and local mosquito species can all change bite pressure. Treat blood type as one small clue, not a reliable prediction of who will be bitten most.

Can I change how attractive I am to mosquitoes?

While you cannot change your blood type or CO2 output, you can reduce mosquito attraction by wearing light-colored clothing, reducing skin bacteria through regular bathing, and avoiding outdoor activity during peak biting hours. The most effective strategy remains using EPA-registered repellent consistently.

How much does blood type matter for mosquito bites?

Blood type is one attraction factor, not a forecast. Type O may raise baseline appeal in some studies, but CO2 output, skin microbes, body heat, sweat, and repellent habits dominate real-world bite pressure.