A person's blood type and clothing color attract mosquitoes, explains an article published by Time Magazine that discusses a University of Florida study. Mosquitoes prefer type O blood over type A or B blood and darker clothing over lighter clothing.
People who are overweight, people who have recently drank alcohol and people who have exercised recently tend to emit higher amounts of carbon dioxide, which attracts mosquitoes, explains Time Magazine. Mosquitoes are also attracted to other chemicals, such as lactic acid. The study also notes that when a person moves around, it helps mosquitoes distinguish that person from the background.