Why do mosquitoes bite some people more than others?

        Scientists have identified several proteins found in mosquitoes’ antennae and heads that latch on to chemical markers, or odorants, emitted from our skin. These markers are produced by the natural processes of our bodies and, like neon signs, they let the mosquitoes’ smell center know you’re around (though the process that then guides them to you is not well understood). Flies and mosquitoes share a number of the same genes that dictate production of these odorant-binding proteins, which have specific sites that will catch or bind with certain chemicals in the air. Some scientists suggest that certain characteristics attract mosquitoes, thereby leading us to have more bites than others. Some of the top candidates: the amount of carbon dioxide in the breath, pregnancy, body temperature, alcohol and odorant markers based on blood type.

       Blood-type markers are chemicals released by people of a specific blood type – so if someone with AB blood emitted a marker, it would be different than that released by B. One study found persons with Type O blood suffered more mosquito landings because of the odorant markers they emit than any other blood type, making their juices a hot commodity for blood banks, as well as Asian Tiger Mosquitoes, which carry West Nile Virus. Not only were Type O’s more likely to be landed on, but the study found that for any blood type, people who secreted a chemical marker about their blood type through their skin (both blood type and secretor status are determined by genes) were bitten much more than non-secretors; 24 percent in the case of the Type O’s. Other researchers estimate about 15 percent of the population, based on their genes, don’t emit chemical markers of their blood type through their skin and saliva, so something else has to be calling the mosquitoes to them.