Sweet Blood Doesnt Attract Mosquitoes: Here is What Actually Attracts Them According to Science

At night, you hear the constant buzzing of a mosquito. By morning, there’s a fresh bite right on your cheek. Meanwhile, your partner slept peacefully through the night. During a walk with friends, you’re the one constantly swatting at tiny attacks on your legs, arms, and back. Like tiny vampires craving fresh blood, mosquitoes seem to prefer certain people… and you might feel like you’re their favourite target. In reality, though, the explanation is a bit more complex.

Sweet blood and mosquito bites: myth or reality?

You’ve probably heard that mosquitoes are especially attracted to sweet blood. In truth, this idea has absolutely no scientific basis. Mosquitoes are not capable of detecting the sugar concentration in human blood.

What they are extremely sensitive to, however, is smell. And we’re not talking about perfume or vanilla shampoo here, but rather natural body odours. Sweat, for instance, is particularly attractive to mosquitoes. And in this area, people are definitely not equal. Some individuals produce sweat with stronger odours, while others emit very little scent at all. In 2017, neuroscientist Helen Shen explained in the journal PNAS that “humans release hundreds of odorant molecules into the air.” Mosquitoes can detect these molecules and use them to locate us. Gregory L’Ambert, head of the Methods and Research unit at the Mediterranean Coastal Mosquito Control Agency, explained in 2014 that mosquitoes have an extremely powerful sense of smell. In fact, they can detect nearly 150 different chemical compounds emitted by the human body. In other words, it’s not sweetness in your blood that draws them in – it’s your body scent.

Mosquitoes are highly sensitive to carbon dioxide

Smell isn’t the only factor that attracts mosquitoes to certain people more than others. These insects are also highly sensitive to the level of carbon dioxide we exhale. Mosquitoes can detect carbon dioxide from as far as 100 feet away. And several factors influence how much CO2 a person releases into the air, including alcohol consumption, body weight, and body temperature. One group of people is particularly targeted because of this: pregnant women. According to a study published in the British Medical Journal in 2000, pregnant women emit about 21% more carbon dioxide than the average person. That higher level of CO2 essentially makes them easier for mosquitoes to locate.

The tiger mosquito’s preference for blood type O

Another factor that may influence mosquito attraction is blood type. The tiger mosquito, known scientifically as Aedes albopictus, is a species capable of transmitting diseases such as dengue and chikungunya. A Japanese study conducted in 2004 found that tiger mosquitoes were more attracted to individuals with blood type O. People with this blood type were shown to have an 85% higher likelihood of attracting mosquitoes, compared with about 45% for other blood types. So while the idea of “mosquito skin” isn’t entirely accurate, certain biological factors – including scent, carbon dioxide output, and blood type – can make some people far more appealing targets than others. In short, if mosquitoes always seem to choose you first, it’s probably not your imagination. Your body might simply be sending signals they find irresistible.