Mosquitoes are generally more attracted to people with blood type O than to those with other blood types. Studies have shown that mosquitoes land on individuals with type O blood nearly twice as often as on those with type A blood, and they prefer type O blood feeders over others in controlled experiments. Blood type B falls somewhere in the middle, while type A is the least attractive to mosquitoes. This preference may be related to specific proteins or antigens present in type O blood, which mosquitoes might be able to sense through chemical signals on the skin, especially in "secretors" who emit these blood type antigens in their bodily fluids
. However, blood type is only one of several factors influencing mosquito attraction. Other important factors include carbon dioxide exhalation, body odor, body heat, skin bacteria, clothing color (dark colors attract more), and recent physical activity, which can increase lactic acid and heat on the skin, making a person more attractive to mosquitoes
. In summary, people with blood type O tend to attract more mosquitoes, but a combination of blood type and other physiological and environmental factors determines how much a person is bitten.
