Ever wondered why mosquitoes bite you while everyone else seems to escape untouched? It is not your imagination, or your perfume. These tiny vampires are far more advanced at detecting humans than we ever realised.
A groundbreaking study from the University of California San Diego, published in Proceedings of the National Academy of Sciences (PNAS), has revealed new insights into how mosquitoes detect humans and why they bite some people more often than others.
How mosquitoes detect humans and why they bite you more
We have known for years that mosquitoes can sniff out the carbon dioxide in our breath, but until now, scientists weren’t sure exactly how they do it.
The research team used advanced 3D imaging to study the mosquito’s sensory hairs, known as sensilla, located on their antennae and mouthparts. They discovered that these structures contain specialised neurons with multiple receptors that detect human scent, body heat, and the carbon dioxide (CO₂) we breathe out.
This combination of signals helps mosquitoes zero in on humans with surprising accuracy. Your unique body chemistry – the mix of compounds released through your skin and breath – could make you more appealing, which might explain why some people always seem to be mosquito magnets.
A scent trail mosquitoes can’t resist
While CO₂ does not attract most other insects, for mosquitoes it acts as a powerful cue that a potential blood meal is nearby. Once they detect it, they can track a person from surprisingly far away, which explains why no amount of frantic swatting seems to help once they’ve locked on.
In South Africa, where mosquitoes thrive in warm, humid regions and malaria remains a concern in many parts of the country, these findings could pave the way for smarter repellents that block mosquitoes’ ability to detect humans.
Until then, experts recommend sticking to tried-and-tested defences like long sleeves, insect repellent, and citronella to stay bite-free this summer.
