Mosquitoes are common blood-feeding insects. Some individuals attract more mosquito bites than others, leading to widespread curiosity about the factors influencing this preference. Among theories, the idea that mosquitoes favor or dislike certain blood types frequently arises. Understanding what truly draws these insects can help demystify why some people are more prone to bites.
Do Mosquitoes Dislike Certain Blood Types?
Scientific studies explore whether blood type plays a role in mosquito attraction. Research indicates that while some preferences exist, blood type is not the most significant factor determining who gets bitten. Studies have shown that mosquitoes, particularly Aedes aegypti, may land on individuals with Type O blood more often than those with Type A, with Type B falling in between. One study found that mosquitoes landed on people with Type O blood nearly twice as often as those with Type A.
Approximately 85% of people secrete chemical signals through their skin indicating their blood type. Mosquitoes appear more attracted to these “secretors” regardless of their specific blood type. While Type A blood might be less attractive to mosquitoes compared to Type O, no specific blood type guarantees complete protection or causes mosquitoes to “dislike” a person. This suggests that while blood type may contribute a minor influence, it is not the primary determinant of mosquito attraction.
What Really Attracts Mosquitoes?
Mosquitoes use sensory cues to locate human hosts, with factors far more influential than blood type guiding their decisions. One primary attractant is carbon dioxide (CO2), detectable up to 150 feet away. The amount of CO2 exhaled, which can vary with body size or physical activity, serves as a primary long-range signal.
Beyond CO2, a person’s unique body odor and skin chemistry play a substantial role. The skin’s microbiome metabolizes compounds in sweat and sebum, producing a complex mixture of volatile organic compounds highly attractive to mosquitoes. Specific chemicals in sweat, such as lactic acid, ammonia, and fatty acids, are potent attractants. Lactic acid, which increases with physical activity, is a particularly strong lure, often acting synergistically with CO2.
Mosquitoes also detect body heat, using it as a close-range cue to pinpoint a target. Warmer individuals tend to be more attractive. Visual cues, such as dark clothing (black, navy, or red) or being a large, moving object, can make a person more visible and easily targeted. These combined factors create a unique chemical and thermal signature that guides mosquitoes to their preferred hosts.