It has taken decades of research, but scientists are close to working out why mosquitoes bite some people, and not others.  It comes down to a complex trifecta of carbon dioxide, body temperature and body odour that makes some people more inviting to mozzies than others. Mosquitoes first use carbon dioxide (CO2) to track their quarry, much like I use my well-honed sense of smell to track down a freshly baked apple pie. CO2 is emitted by its mammalian blood donor, which mosquitoes can detect from up to 50 metres away. They fly upstream using the shift in concentration of CO2 along this stream to orient themselves. Subsequently people that emit higher levels of CO2 are more attractive from a distance such as those that are exercising or others that have a higher resting metabolism, such as larger individuals. In general, this means men are more likely to attract mosquitoes than women, children are less susceptible than adults, and full-figured individuals including pregnant women are more attractive than their slimmer counterparts. As mosquitoes get closer, thermal detectors that can clock temperature differences of around 2.5 degrees kick in and if the target is not at the right temperature, they won’t land. Anything over 40 degrees is getting too hot, but normal human body temperature is just right. The final stage is related to body odour which is where it starts to get complex but super cool.