We’re all probably familiar with the itchy red bumps that develop after we’re bitten by mosquitoes. Most of the time, they’re a minor annoyance that goes away over time. But do you ever feel like mosquitoes bite you more than other people? There may be a scientific reason for that! What attracts mosquitoes to certain people? A variety of factors can attract mosquitoes to you. Here are a few: CARBON DIOXIDE We all emit carbon dioxide when we breathe out. We also produce more when we’re active, such as during exercise. Mosquitoes can detect changes in carbon dioxide in their environment. Research has shown that different mosquito species may respond differently to carbon dioxide. An increase in carbon dioxide can alert a mosquito that a potential host is nearby. The mosquito will then move toward that area. BODY ODOR Mosquitoes are attracted to certain compounds that are present on human skin and in sweat. These compounds give us a specific odor that can draw mosquitoes in. Several different compounds have been identified as being attractive to mosquitoes. Some that you may be familiar with include lactic acid and ammonia. Researchers are still investigating the causes of the variations in body odor that make certain people more attractive to mosquitoes. Causes could include genetics, certain bacteria on the skin, or a combination of both. Body odor itself is determined by genetics. If you’re related to someone who is often bitten by mosquitoes, you may be more susceptible too. A study published in 2015 found that mosquitoes were highly attracted to odors from the hands of identical twins. Skin bacteria also play a role in body odor. A 2011 study found that people with a high diversity of microbes on their skin were less attractive to mosquitoes. The researchers also identified specific species of bacteria that were present on people who were highly and poorly attractive to mosquitoes. Research has shown that mosquitoes are attracted to the color black, but little is known about why. Regardless, if you’re wearing black or other dark colors, you may be more attractive to mosquitoes. HEAT AND WATER VAPOR Our bodies generate heat, and the levels of water vapor close to our skin can vary depending on the surrounding temperature. As a mosquito gets closer to us, it can detect heat and water vapor. This can play a role in whether it decides to bite. One study found that mosquitoes move toward nearby heat sources that are at a desired temperature. These factors can also be important for host selection. Other animals may have differences in body temperature or water vapor throughout their bodies. These variations could be unattractive to mosquitoes that prefer to feed on humans. Mosquitoes could learn to prefer a certain type of host! They may associate certain sensory cues, such as scents, with hosts that have given them a good-quality blood meal. An older study of transmission of mosquito-borne disease found that 20 percent of hosts accounted for 80 percent of disease transmission in a population. This could mean mosquitoes are choosing to bite only a fraction of people within a population. A small 2002 study looked at the effects of alcohol consumption on attractiveness to mosquitoes. The researchers found that people who had consumed beer were more attractive to mosquitoes than people who had not. Studies have shown that mosquitoes appear to be more attracted to pregnant women than non-pregnant women. This may be because pregnant women have a high body temperature and exhale more carbon dioxide.