Many people have experienced the same frustrating scenario. A group spends time outdoors together, but only one or two people return home covered in mosquito bites.
Scientists say this is not simply a matter of bad luck.
A growing body of research suggests mosquitoes carefully select their targets. They use a combination of smell, body chemistry, heat and visual signals to identify potential hosts.
Recent findings highlighted in the journal Nature show that mosquitoes first locate people by detecting carbon dioxide released through breathing. Once they move closer, a person’s natural body odour becomes one of the most important factors in determining whether they get bitten.
Researchers identified dozens of skin-related compounds that influence mosquito behaviour. Among the strongest attractants is a chemical called 1-octen-3-ol, which forms as skin oils naturally break down.
The findings add to earlier research showing that mosquitoes rely heavily on chemical signals rather than chance when choosing whom to bite.
For years, many people believed blood type was the main reason some individuals attracted more mosquitoes. While some studies suggest people with Type O blood may receive more bites, scientists increasingly view body scent as the more important factor.
Research from Rockefeller University found that people with higher levels of naturally occurring carboxylic acids on their skin attracted significantly more mosquitoes than others. Scientists believe genetics partly influences how these compounds develop on the skin.
Carbon dioxide and body heat help mosquitoes find targets
Mosquitoes do not rely on scent alone.
Every person exhales carbon dioxide, which female mosquitoes can detect from considerable distances. The insects use the gas as an early signal that a potential host is nearby.
As a result, people who produce larger amounts of carbon dioxide often attract more mosquitoes.
This includes larger adults, pregnant women and people who have recently exercised.
After detecting carbon dioxide, mosquitoes use body heat and moisture to pinpoint their target.
Scientists say this process helps explain why people often notice more mosquito activity after physical exercise or during hot, humid weather.
Research has also shown that clothing colour can influence mosquito behaviour.
Studies indicate that mosquitoes more easily identify people wearing darker colours such as black, navy blue and red. In contrast, lighter shades such as white, beige and light green appear less attractive.
Proven ways to reduce mosquito bites
Health experts recommend focusing on prevention methods supported by scientific evidence.
These include using insect repellents containing DEET, picaridin or oil of lemon eucalyptus. Experts also advise wearing long sleeves and trousers, especially during dawn and dusk when mosquito activity often peaks.
In addition, removing standing water around homes can reduce breeding sites.
Window screens and outdoor fans can also help because mosquitoes struggle to fly in strong airflow.
Scientists say understanding mosquito attraction could lead to more effective repellents and disease prevention strategies in the future. This research may prove increasingly important as mosquito-borne illnesses such as dengue, malaria, Zika virus and West Nile virus continue to affect millions of people worldwide each year.
