Summer is mosquito season. Yet, although I spend most of mine in the forests of northern Wisconsin (USA), I manage to return home unscathed. Not everyone is so lucky, because lo and behold, mosquitoes have their preferences. But why do they sting some people more than others?
We must first talk about their main target: blood. Contrary to popular belief, mosquitoes do not feed on animal blood. In fact, only females bite, and this for reproductive needs. However, scientists have discovered that they have a favorite blood group.
In 2004, a study showed that they were more attracted to people with blood group O. This was confirmed by another study, carried out in 2019: mosquitoes, if given the choice, showed a preference for donors universal.
Attracted by some
The bacteria present on his skin can also make an individual more or less attractive. Mosquitoes also react to certain body fumes. They have organs called maxillary palps that allow them to detect the carbon dioxide emitted by their prey. So if you’re a strong gasser, so to speak, you’re likely to please them. (This is also why pregnant women are mosquito magnets: according to studies, they emit about 21% more CO2).
Substances released by sweat, such as ammonia and lactic acid, also seem popular. Individual differences in attractiveness could have a genetic origin. Researchers confirmed this hypothesis in a study of twins, carried out in 2015.
Certain circumstantial factors could also play a role. Although odors are their primary guide, mosquitoes’ rather crude visual system is used to detect potential targets. So bright colors will (also) attract the attention of these dear critters.
Another unexpected culprit: beer. As entomologist Grayson Brown explained to CBS News in 2016, the reason is unclear, but the following hypothesis can be advanced: “alcohol raises the body temperature of drinkers and makes them sweat more” and “the C02 that escapes from a bottle of beer when it is opened could also attract them”. What if, therefore, sobriety was a natural mosquito repellent?