It’s not a myth that mosquitoes bite some people more than others and scientists have identified a number of factors that could play a role in this:
Factor 1: Carbon Dioxide and, therefore, body size.
Only female mosquitoes bite (males rely on the nectar of flowers); they do so because they need proteins and other compounds (present in our blood) to produce and develop their eggs.After they have consumed enough blood, the mosquito will rest for a couple of days before laying her eggs. Once this is complete, she is ready to bite again. Female mosquitoes can lay a set of up to 100 eggs about every third night after mating only once. They typically lay as many as three sets before dying. Source: MegaCatch and WesternExterminator.
When they need blood, they go looking for their targets and one of the key ways of doing that is by smelling the carbon dioxide.
Mosquitoes have been found to get attracted to people with higher body temperatures.
Exercise, therefore, makes you prone as it increases your body temperature; also, when you exercise, your body uses more oxygen and produces more CO2.
Factor 1 and 2 also explain why pregnant women (they exhale 21% more CO2, and have higher body temperatures) are highly targeted by mosquitoes.
Factor 3: Blood group.
Studies show that mosquitoes prefer to feed on blood type O more than any other blood type; the difference is significant when compared to blood type A.
Factor 4: Body odour.
Some compounds or bacteria on the skin produce smells that make it easier for mosquitoes to locate us.
E.g., lactic acid, which builds up in the body when we exercise, or uric acid, which some people are genetically more predisposed to produce.
Drinking beer (because of the way it affects the body odour or the increase in temperature it causes) has also been found responsible for attracting mosquitoes.
