What Attracts Mosquitoes to Us?

Why Are Mosquitoes Attracted to Some People?

Mosquitoes are attracted to our breath, sweat and blood type.
Mosquitoes are attracted to our breath, sweat and blood type. Haykirdi/E+/Getty Images

Mosquitoes are more attracted to some people than others, but what brings them flying and makes mosquitoes bite?

What Attracts Mosquitoes?

There are a number of things that mosquitoes like, and what may be attractive to one species may not be for another. Some are attracted to the blood of humans, others to animals. And, because there are more than 70 species -- of 2,700 worldwide -- that transmit diseases when they bite, it can be tricky to pinpoint an attractant.

(Source: USDA Agricultural Research Service)

Additionally, human skin produces more than 350 odorous compounds, and many of these attract mosquitoes - as well as other biting insects. But what has been found to be most attractive to mosquitoes are our breath, sweat, blood type ... and smelly feet! 

Our Breath Attracts Mosquitoes

Carbon dioxide is considered to be the greatest attractant to mosquitoes, and they can sense it from more than 50 yards away. Why is this important? Because we breathe out carbon dioxide, so it is virtually impossible to keep mosquitoes completely away. In fact, when the female mosquito (which is the one that bites) sense carbon dioxide (that is, our breath), she will fly in a zigzag pattern, back and forth, until she finds the source -- the people breathing.

But, there also are things in our breath that attract the mosquito to one person over another once it gets close to the group.

For example, larger people tend to exhale more carbon dioxide, so they can be more attractive to the mosquito. And, if you ever noticed that a pregnant woman seemed to attract more mosquitoes, you were probably right - they, too, tend to breathe out more carbon dioxide.

Fortunately for those heavier breathers, carbon dioxide is not the only trait that draws mosquitoes.

In fact, even if they are the reason mosquitoes are attracted to a group, the incoming bug is  likely to select another person in a group if it finds a person who even more compelling when it gets near (kind of like that hot guy or girl who saw your friend from across the room, but zoomed in on you once he or she got near!)

Movement, Sweat, and Heat Bring Mosquitoes Flying

Like that guy or girl, mosquitoes are attracted visually, so movement can bring them to you instead of the person sitting still next to you. And the heat and sweat caused by such movement can make a person even more attractive. So if some of the people are very active (playing volleyball, tennis, or other sport), the combination of their increased breathing, movement, sweat, and heated bodies are very likely to attract the mosquitoes over the person who is sitting very still.

Unless, that is, that person is sitting and drinking beer. A study by the National Center for Biotechnology Information (NCBI) measured the ethanol content in people's sweat, and their sweat production and skin temperature before and after they drank 12 ounces of beer. The results showed more mosquitoes landed on the people after they drank the beer than had before they did.

So, if you've always believed that can of beer can make a guy more attractive to females, you're right! If you're talking about the females of the mosquito family anyway.

Your Blood Type Can Make You More Attractive to Mosquitoes

No matter how careful you are, if you have the right blood, you may be mosquito main target. Another NCBI study found that people with Type O blood attracted more mosquitoes than any other blood type. And, even more interesting, if the mosquito can tell what blood type you have by its odor, it will be more likely to bit you! Unfortunately, your blood type and its distinguishing odor are carried in your genes, so you really can't do anything about it.

Mosquitoes Like Smelly Feet 

Although sweaty, unclean, smelly feet may make other people in your group sit farther away from you, they will bring the mosquitoes near!

According to USDA, smelly feet are kind of like Limburger cheese; and mosquitoes are very attracted to Limburger cheese! To add to that, when CO2 (e.g., our breath) was combined with smelly socks, many common species of disease-transmitting mosquitoes came flying.

Although we do have some control over the smell of our feet, we can't really stop breathing, change our blood type, or even sit still forever. But the understanding of the chemicals, compounds, and characteristics that attract does help researchers find new ways of controlling mosquitoes. As USDA/ARS noted, "If we can attract the mosquitoes to a trap, we can use this information to assess the mosquito distribution and population and develop ways to control them."

Find out more about mosquito control at Mosquito Control: What Really Works?