Why Do Mosquitoes Bite Some People More? The Secret Is in Your Genes

Key Takeaways

• Mosquitoes really do bite some people more than others — they have "favorites."
• Part of it is body odor the body produces, which is influenced by genes.
• Other factors matter too — exhaled carbon dioxide, body temperature, and blood type.
• It's a fun topic, but backed by real research.

You go on a picnic with friends and come back with a dozen mosquito bites, while the friend next to you barely has any? You're not imagining it. Mosquitoes really do have "favorites," and part of the reason is our genes. Let's see why.

What Do Mosquitoes Choose Their Targets By?

Female mosquitoes (the ones that bite) use several cues to find prey — the carbon dioxide we exhale, body heat, and very importantly the "body odor" our skin releases. Mosquitoes have highly sensitive smell receptors, and certain odors attract them more. In fact, research testing volunteers' skin odor identified some people who are clear "mosquito magnets," and these differences stayed stable over several years (De Obaldia et al., Cell, 2022).

Body Odor and Genes

What's interesting is that our body odor is partly determined by genetics. Twin studies found identical twins (same genes) have more similar levels of mosquito attractiveness than fraternal twins, estimating the heritability of attractiveness to mosquitoes at around 0.62 (Fernández-Grandon et al., PLoS ONE, 2015). This suggests genes play a real role in how "tasty" we are to mosquitoes. And when researchers analyzed skin chemicals, they found that highly attractive people produce more carboxylic acids on their skin than people mosquitoes tend to ignore (De Obaldia et al., Cell, 2022).

Other Factors That Attract Mosquitoes

Besides genes, research mentions other factors — people who exhale more CO2 (larger individuals or pregnant women), those with higher body temperature, and those who just exercised (lactic acid and sweat). Interestingly, most of our body odor doesn't come from fresh sweat but from skin bacteria breaking it down — and research found that people with a higher abundance but lower diversity of skin bacteria tend to be more attractive to mosquitoes (Verhulst et al., PLoS ONE, 2011). Some studies even found a link with blood type, though that evidence is weaker. This connects with genes and taste/smell perception.

So What Can We Do?

Even though we can't change our genes, we can reduce the odds of getting bitten — use effective mosquito repellent, wear light-colored long sleeves, eliminate standing water around the house, and shower after exercise to reduce sweat odor and skin bacteria. Understanding why we're a "target" helps us protect ourselves more precisely.

From the Geneus DNA Team

Mosquitoes' biting preferences are a fun example of how much genes weave into our daily lives — even something small like body odor has genetics behind it. If you want to know yourself at the DNA level more deeply, check out a DNA test.

References

1. Fernández-Grandon GM, Gezan SA, Armour JAL, Pickett JA, Logan JG. Heritability of Attractiveness to Mosquitoes. PLoS ONE. 2015;10(4):e0122716. PLOS ONE
2. De Obaldia ME, Morita T, Dedmon LC, et al. Differential mosquito attraction to humans is associated with skin-derived carboxylic acid levels. Cell. 2022;185(22):4099–4116. NCBI PMC
3. Verhulst NO, Qiu YT, Beijleveld H, et al. Composition of Human Skin Microbiota Affects Attractiveness to Malaria Mosquitoes. PLoS ONE. 2011;6(12):e28991. PLOS ONE