When you’re donating blood at your local blood bank, they love it when a type O comes in. It turns out mosquitoes like them, too. A 2019 study published in the American Journal of Entomology found that when given feeders of different blood types (A, B, AB, and O), the mosquitoes spent the most time on the feeder of the O blood.
The preference of mosquitoes toward a specific blood type could have something to do with the different blood antigens (per Healthline). For example, A has the A antigen, B has the B antigen, and AB has both antigens on the red blood cell surface. O, on the other hand, has a precursor antigen known as H. This was further shown in the Journal of Medical Entomology research, where participants with the H antigen attracted more mosquitoes than those with the other antigens. In the group, O secretors had 83.3% of mosquitoes landing on them compared to 46.5% landing on A secretors. So, your blood type could help to make you more attractive if you’re O.
However, Pfizer states that research into the attraction of mosquitoes to specific blood types could be flawed and speculative. Therefore, skin odors and microbiota are a more critical factor.