A brand new scientific study shows that while mosquitos have a favourite prey (usually birds) to feast on, greater than 80% of mosquitoes still show an innate preference for human odour. Once they first connect our odour with a tasty meal, they actually receive a hit of dopamine which locks us in as one of their favourite places to eat.
They also found that mosquitos actually assess the level of danger that the host will exhibit when attempting to eat. The more swatting you do dissuades them from returning (clearly the scientists have never been on a swampy portage!).
Hopefully this leads to new research to mask our delicious scents, especially since a 2010 research paper showed that Mosquitoes are inheriting DEET resistance!