Only female mosquitoes bite humans, and they do so because they need blood to reproduce. Over time, they’ve evolved an advanced sensory system that helps them locate the most suitable hosts.

The human body constantly releases signals that act like a tracking system for mosquitoes. Some people simply emit stronger or more attractive signals than others.

Carbon Dioxide: The Strongest Signal

One of the most important factors is carbon dioxide (CO₂). Every breath releases CO₂, and mosquitoes are extremely sensitive to it.

People who are taller, have more body mass, or are physically active tend to emit more CO₂, making them easier for mosquitoes to detect. Body heat works alongside CO₂, guiding mosquitoes directly toward their target.

Body Odor and Skin Bacteria

Natural body odor plays a major role. Human skin is home to millions of bacteria that produce specific chemical compounds. This creates a unique scent profile for each person.

For mosquitoes, certain scent combinations are especially appealing. This has nothing to do with cleanliness—it’s a biological trait that makes some people more attractive than others.