You can always count on a mosquito bite to ruin a fun summer evening. But you've probably noticed that one of your friends (or maybe it's you) seems to have an uncanny ability to attract all the little fiends, while the rest of your crew gets off relatively easily. Although scientists don't know the full picture yet, they do have some pretty good ideas about why the little guys are so attracted to certain people — and how to make it stop.You've probably heard that your blood type, sweat, or a multitude of other things can attract mosquitoes. While some of those "attractions" are more plausible than others (sorry, it's definitely not your blood sugar content), Joe Conlon, PhD, technical advisor to the American Mosquito Control Association , says it all comes down to the secretions your skin's putting out."There’s no question that everyone has a different odour about them," says Dr. Conlon. "The mosquitoes have honed in on this and have determined that some people should be on the menu more often than others."One major factor is the amount of carbon dioxide you release. "Carbon dioxide acts more as an excitant," Dr. Conlon explains. "It’s not necessarily going to get them to land on you, [but] it gets them off of the leaf and into a pursuit mode." Some people, such as pregnant women, definitely exude more carbon dioxide than others.