Summer means mosquitoes — and if it feels like they always specifically seek you out, you may not be imagining it. While mosquitoes are drawn to a range of signals — including the carbon dioxide you exhale, body heat, sweat compounds such as lactic acid, skin bacteria, and even visual cues such as movement and darker clothing — some research suggests blood type may also play a role in how attractive a person is to mosquitoes.
Some controlled experiments have found that mosquitoes land on people with type O blood about twice as often as those with type A, with preferences for type B and type AB typically falling somewhere in-between. Researchers have theorized that this pattern may be linked to subtle differences in chemical signals tied to blood type antigens that can appear in skin secretions and influence body odor. But the research into this is limited, and scientific opinion remains divided on the significance of the studies that have been conducted so far.
Regardless, when it comes to mosquito preferences, blood type is only one piece of the puzzle. The effect appears to be relatively modest compared to stronger attractants such as carbon dioxide output, body odor, and skin microbiome differences, which vary widely from person to person. Mosquito attraction is also highly context dependent, changing with activity level, environment, and time of day. Researchers continue to study how those factors interact, and why some people consistently appeal to mosquitoes more than others.
