Many people have experienced it: a peaceful evening outdoors where one person ends up covered in mosquito bites while everyone else seems untouched. It’s not bad luck — mosquitoes don’t bite randomly. Only female mosquitoes feed on blood, and they are guided by highly sensitive biological sensors that detect carbon dioxide, body heat, and chemical scents released from human skin. People who breathe out more CO₂ — such as those who are taller, physically active, or have higher body mass — become easier targets. Skin bacteria also produce unique body odors, and certain scent profiles are naturally more appealing to mosquitoes, regardless of hygiene. Even blood type plays a role, with type O individuals attracting more bites than others.

Additional factors strengthen mosquito attraction. Sweat and lactic acid released after exercise act as powerful signals, while dark clothing makes people more visible to these insects. Alcohol consumption, hormonal changes, perfumes, and skincare products can subtly alter body chemistry, increasing appeal. Genetics is the biggest influence of all, determining up to 70% of mosquito attraction, which explains why some people are lifelong targets. Although biology can’t be changed, bites can be reduced by using repellents, wearing light-colored clothing, avoiding peak mosquito hours, and removing standing water nearby. Mosquitoes aren’t choosing favorites — they’re simply following science.