Why Are Mosquitoes Attracted to Me and Not Others?

  • Written By Dan Edwards on June 23, 2018
    Last Updated: December 10, 2020

Sometimes it can seem that these pesky bloodsuckers have a real preference over which of your friends they feed upon. Perhaps it’s you who always falls victim to mosquito bites, while others around you are left alone to enjoy themselves.

Some people who always fall victim to mosquito bites are convinced that their blood must taste much better than others, but can this really be true? Does the person constantly waving their arms about in the yard really have higher quality blood than someone else who doesn’t suffer?

In this article, we examine the potential factors which may make some people a more attractive meal to hungry mosquitoes.


Why Do Mosquitoes Seem to Prefer Some People and Not Others?

When you come under attack from a mosquito, it is more of a ‘stabbing,’ than a bite. Many species of female mosquitoes need to bite animals and people to survive, and use a long tube called a proboscis to stab through the skin and into the blood vessels beneath. Once they’ve found a suitable vessel, they extract the blood through their proboscis, much like using a straw.

mosquito feeding close

It isn’t the puncturing of the skin which causes irritation. Mosquitoes have specialized saliva which is common in parasitic biting insects. This saliva contains certain chemicals and proteins which act as anticoagulants to prevent the blood from clotting. Before the mosquito begins feeding, it will inject this saliva into the skin to enable it to feed as long as it likes.

The chemicals and proteins in this saliva are responsible for the itching and irritation felt after a mosquito bite. Your immune system detects this foreign substance and immediately acts defensively. In effect, you’re experiencing a very mild allergic reaction as your antibodies fight off the intruding saliva.

mosquito closeup bites

If you’re at top of the menu for mosquitoes, you’re probably rather familiar with the pain and irritation caused by their bites. Research has suggested a number of reasons why mosquitoes may gravitate towards you and leave your friends alone. Some factors are out of your control, but others can be mitigated to reduce your attractiveness.

Let’s take a look at each of these factors below:

Blood Type

If you have ever been told “you must have sweet blood,” when a friend sees all your bites, there could actually be some truth to that statement.

It is perhaps unsurprising that mosquitoes could prefer one blood type to another. After all, they bite us in order to consume proteins from our blood, so have a reason to be fussy.

squashed mosquito

Research has shown that mosquitoes seem to prefer Type O blood more than Type A blood. In a controlled environment, mosquitoes landed on people with Type O blood almost twice as frequently as those with Type A. During the study, participants with Type B blood were more preferable than Type A but less preferable than Type O.

It is also understood that around 85 percent of people release a chemical signal from their skin which reveals what blood type they have. Regardless of the blood type, mosquitoes are more attracted to people which secrete these signals than those who do not.

Breath

Mosquitoes also locate their prey by sniffing out carbon dioxide and following the trail to a living, breathing creature they can bite. Using a specialized organ known as a ‘maxillary palp,’ they are able to detect carbon dioxide in the air from up to 164 feet away.

Of course, all of us breathe out carbon dioxide, but some people will exhale more than others. Generally, larger individuals will exhale greater quantities of carbon dioxide over the same period of time, when compared to smaller individuals. This explains why, in a mixed group of people, children are usually bitten less than adults.

Sweat and Exercise

Another way mosquitoes locate their prey is by sensing the chemicals which are expelled in sweat. This method is used at a much closer range than carbon dioxide detection.

Our sweat can contain lactic acid, ammonia, and uric acid, among others. All of these substances are attractive to mosquitoes. They also prefer to feed on people with higher body temperatures.

Exercise increases your body temperature and the amount of lactic acid in your body. Therefore, if you have been out playing sports, you’ll probably seem relatively attractive to mosquitoes.

However, cutting out exercise does not necessarily mean mosquitoes will leave you alone. There are genetic factors which influence how much uric acid each of us naturally secretes, so mosquitoes may still hunt you down, whether you quit sports or not.

Alcohol

Studies have shown that drinking a single 12-ounce bottle of beer can make you much more attractive to biting insects. Originally, scientists believed this must be the result of increased body temperature caused by alcohol consumption, or the excretion of ethanol in the sweat.

However, after further trials, these individual factors didn’t seem to make any difference to the frequency of mosquito landings. Therefore, researchers are still unsure as to why mosquitoes prefer people who drink beer.

Pregnancy

If you’re pregnant, mosquitoes are going to love you. As if pregnancy wasn’t hard enough, pregnant women also attract almost twice as many mosquitoes than non-pregnant individuals.

During pregnancy, two factors which attract mosquitoes are intensified. Pregnant women exhale around 21 percent more carbon dioxide, and also have an increased body temperature. Unfortunately, if you are expecting, you can also expect to receive unwanted visits from mosquitoes.  

Can You Tell If You’ve Been Bitten by a Mosquito If There Is No Mark?

It is very rare that an individual would become immune to the effects of mosquito bites, but it has occurred in the past. In most of these cases, the individual has been exposed to mosquito bites by a certain species repeatedly over extended periods. Generally, these circumstances will only occur in research facilities.

Immunity in these cases is a resistance to the allergic response caused by mosquito saliva. Initially, the immune system feels threatened by this unknown, foreign substance. It reacts defensively, resulting in inflammation and itching. Over time, the immune system comes to recognize mosquito saliva, eventually no longer responding to it.

A lack of reaction to mosquito bites is incredibly rare. If you do not have a mark or any irritation on the skin, it is more likely that you simply haven’t been bitten.

Mosquito bites will present themselves in the following ways:

Lumps

When bitten, your body will usually react within a few minutes. The first sign of a mosquito bite is a swollen, pale lump. The lump is often soft and puffy to the touch. There may be a tiny red dot in the center, but in many cases, there will not. This lump generally hardens over the next 24 hours.

mosquito bite on hand

Inflammation

Inflammation and swelling are often one of the first indications that you have become the victim of a mosquito bite. As previously mentioned, inflammation is a response by your immune system in an attempt to protect you from an unknown substance. The area may also become red as the surrounding blood vessels dilate to try and remove irritants.

mosquito bites on knee

Itching

This is certainly the single most annoying symptom of mosquito bites. Itching is your skin’s natural reaction to the inflammation. Itchy mosquito bites are irritating, but can also pose a risk of infection. You must try your best to avoid scratching the skin.

Mosquito bites on ankle

If the surface of the skin becomes broken, bacteria can get inside the wound and cause an infection to develop. Infected mosquito bites will be more painful and take much longer to heal. They can also result in permanent scarring.

If you experience any unusual skin reactions or symptoms which cannot be attributed to mosquito bites, it is advised to contact your doctor to rule out any underlying illness.

Summary

If you’re one of those people who is always itching during mosquito season, and wondering why mosquitoes have to exist, it really could just be because you have better blood than your friends; which is sort of a compliment.

As we have seen, there are a number of factors which can lead to more mosquito bites on you rather than your buddies. Luckily, at least some of these factors can be controlled, but it’s unlikely to be much fun. Who wants to have a cookout and pass on the beer, just so mosquitoes might leave them alone?

Overall, the best method to avoid mosquito bites is to invest in a good quality repellent. That way, those irritating bugs will avoid you, no matter what blood type you have.