[Bit#72] Why Do Mosquitoes Bite Some People More Than Others?

1. Tracking Signals Hidden in Breath: Carbon Dioxide and the Mosquito’s Radar

A mosquito finds you in a room. It buzzes around your ears. This is never a coincidence. Mosquitoes recognize their prey from dozens of meters away. They are equipped with a highly precise, high-performance radar. There is a first signal that this radar detects. What could it be? It is the carbon dioxide we emit when we breathe out.

Mosquitoes have maxillary palps on their heads. These contain specialized neurons called carbon dioxide receptors. These receptors detect even the most microscopic changes in gas concentration in the surrounding air. They are incredibly sensitive. When we exhale, a scent plume is created in the air. Mosquitoes fly in a zigzag pattern along this trail. They detect this signal from up to 50 meters away. It is a terrifying tracking ability.

However, everyone breathes. Why do mosquitoes swarm around specific people? The answer lies in the difference in the amount and concentration of carbon dioxide emissions. Some people emit more carbon dioxide. Those individuals stand out clearly on the mosquito’s radar screen.

People with high metabolic rates are a prime example. When metabolism is active, energy consumption in the body increases. As a result, carbon dioxide, a waste product, is pumped out. This is exactly why larger adults get bitten by mosquitoes more often. The same goes for pregnant women. They emit about 21 percent more carbon dioxide than the average adult woman. This is because their metabolic rate increases and their breathing volume expands.

The period immediately after exercise is also dangerous. Breathing quickens, causing a sharp surge in carbon dioxide emissions. It is the same when you drink alcohol. Metabolism speeds up during the alcohol breakdown process. Your breath becomes heavier. For mosquitoes, you become the most attractive target possible. Your breath is calling the mosquitoes.

2. Ecosystem on the Skin: The Alluring Scent Created by Microbes

Mosquitoes have come near you by following the carbon dioxide. Now it is time for the mosquito to decide its final landing spot. Where will the mosquito land? The answer lies in the scent of your skin. Why does this scent differ from person to person? It is because of the microbes living on your skin.

Millions of bacteria live on our skin. It is a kind of massive microbial ecosystem. These microbes do not stay still. They consume the sweat and sebum on the skin. Then, they actively break them down. Various chemical substances are produced during this breakdown process. Lactic acid is released. Ammonia is pumped out. A component called isovaleric acid is also generated. These mix together to become your unique body odor.

Mosquitoes recognize this combination of chemical substances flawlessly. There is a research result. Some people have a simple variety of microbes on their skin. These are individuals who have an exceptionally high amount of specific bacteria. Such people emit a much stronger alluring scent to mosquitoes. They are emitting a smell that drives mosquitoes crazy.

You must be especially careful between your toes. The microbes living here are very unique. They produce a large amount of a pungent odor component called isovaleric acid. Why do mosquitoes intensively attack the ankles and feet in particular? It is not because you do not wash. It is because the microbes living on your feet possess a deadly perfume that attracts mosquitoes. Your skin ecosystem is tempting mosquitoes.

3. Body Temperature and Blood Type: The Secret of Targets Favored by Mosquitoes

You have passed the carbon dioxide and skin odor tests. Yet, out of several people in a room, the mosquito picks exactly one person to bite. What on earth is the criterion? There is another standard by which mosquitoes activate their radar at the final moment. It is your body temperature and blood type.

Mosquitoes detect heat magnificently. They notice even the slightest temperature difference. They have a precise heat sensor that captures changes as small as 0.05 degrees Celsius. Therefore, people with high body temperatures easily become targets for mosquitoes. This is exactly why people who have a lot of body heat get bitten by mosquitoes so often. Babies or adults with active metabolisms belong to this group. Their bodies are like warm heated floors to mosquitoes.

Blood type is also a very important variable. There is a scientific research result. Mosquitoes exceptionally prefer a specific blood type. Which blood type is it? The answer is type O. According to experiments, mosquitoes landed on people with blood type O nearly twice as often as those with type A or type B. Why is that?

People with type O emit a chemical signal through their skin that says, I am type O. The secret lies in the sugar components. The antigen structures on the surface of red blood cells are different. This sugar component flows out through skin secretions. Mosquitoes recognize this smell instinctively. The blood of type O might be like the sweetest soda to mosquitoes.

Of course, you cannot change your blood type. It is a destiny you are born with. What happens if you have blood type O and also have a lot of body heat? You become the ultimate, irresistible restaurant for mosquitoes. Tonight as well, mosquitoes begin their flight chasing your warm body temperature and sweet blood type signals.

4. Destiny Determined by Genes: Why Am I the Only One Getting Bitten More?

Even if you avoid all the previous conditions, there is an absolute factor you cannot escape in the end. It is the genetic information you inherited from your parents. There is an interesting study conducted on twins. Identical twins, whose genes are completely identical, had almost the exact same frequency and tendency of getting bitten by mosquitoes. On the other hand, fraternal twins, who have different genes, showed a big difference in the degree of getting bitten.

What does this study tell us? It means your genes have already determined whether you have a constitution that easily gets bitten by mosquitoes. Scientists analyze that about 85 percent of overall mosquito avoidance or attractiveness is governed by genetic factors. There is a huge wall that is difficult to change through effort.

How exactly do genes exert their influence? They determine the amount of natural mosquito repellent substances our bodies secrete. Some people produce more chemical components on their skin that mosquitoes instinctively dislike compared to others. Conversely, some people only emit plenty of components that attract mosquitoes.

In the end, people who get bitten less are not cleaner than others. It is thanks to genetically inheriting a natural protective shield that mosquitoes avoid. If you become a target for mosquitoes no matter how hard you wash and stay careful, it is not your fault. It is just a trick of your genes.

Now, all the secrets of why the frequency of getting bitten by mosquitoes differs from person to person have been unlocked. Various causes, including breath, microbes, body temperature, and genes, are precisely intertwined.