It’s a situation that many of us have faced while on vacation with our partner or a friend.
One will be completely covered in mosquito bites, while the other will emerge almost unscathed.
And while red, painful, bumpy bites are bad enough, buzzing attackers can also spread a number of dangerous pathogens and pose a growing health risk in Europe.
So what makes one person more attractive than another to vampire bloodsuckers?
Here MailOnline explains what experts say is and is not the key behind the phenomenon.
Several factors are thought to make one person more attractive to mosquitoes than another.
How big you are and how you breathe
Mosquitoes track their prey by smell and one of the things they look for is carbon dioxide.
Carbon dioxide (CO2) is a gas we exhale when breathing and acts as a reference signal for insects.
However, the amount of CO2 seems to matter. Larger people naturally exhale greater amounts of carbon dioxide and it is for this reason that experts say they tend to be bitten more.
In the real world, this translates to men being bitten more than women, pregnant women being bitten more than non-pregnant women, and adults being bitten more than children.
Dr. Robert Jones, a disease control expert at the London School of Hygiene and Tropical Medicine, said heavier people can also be targets for this reason.
“Among a group of people, the proportion of bites by an individual has been associated with the proportion of total surface area or weight contributed by that individual to the group,” he said.
The same logic is thought to apply to people with a higher breathing rate, such as those who exercise.
Your natural aroma and the bacteria in your body.
People’s unique scent is also thought to play a role in mosquito victim selection.
Our natural smell is determined by a combination of our genetics and the skin microbiota, the community of microscopic organisms that live on the surface of our flesh.
Tests in which people use nylon strips to extract musk and then dangle them in front of swarms of mosquitoes have clearly shown that the insects have a preference when it comes to particular scents.
Similar studies on twins have suggested that genetics could explain up to 67 percent of mosquito attraction.
While there is evidence that personal scent accounts for an important part of mosquito attraction, scientists are still trying to figure out exactly what compounds in our air are responsible and what we can do to mask or reduce them.
Dr Jones said: “We believe that genetic factors and our skin microbiome affect the volatile compounds our body produces and this, in turn, affects our smell.”
Mosquitoes track their prey by smell and one of the things they look for is the carbon dioxide that people exhale when they breathe.
“Some of these compounds have been shown to be attractive to mosquitoes, so if your body produces a lot of these compounds, you may attract more mosquitoes than other people.
“We are interested in finding ways to mask these compounds or alter their relative abundance to make people less attractive.”
Choosing your outfit could make you a target
While smell is mosquitoes’ best sense, it is not the only one, as studies show that insects prefer some colors over others.
Experiments have shown that they have a general preference for red, orange, black or cyan.
On the contrary, the colors green, blue or violet did not attract the attention of the bloodsuckers.
Experts believe that mosquitoes have developed this sense to distinguish between their prey and the environment once they have smelled it.
Mosquito vision is not the same as human vision and all human skin, regardless of its pigmentation, will appear red or orange to insects.
Experts said people could reduce the chance of being bitten by mosquitoes by avoiding wearing colors they find attractive.
Does your blood type really make you more delicious?
One of the most common beliefs is that your blood type, specifically type O, makes you a more desirable meal for mosquitoes.
However, while some studies have shown this to be the case, other evidence has been inconclusive.
Dr. Jones said that, in general, blood type is probably not a major component in mosquito attraction.
“There does not appear to be strong evidence that blood types affect the attractiveness of people to mosquitoes. “Other factors are more important,” he stated.
What about what you eat or drink?
It is claimed on the Internet that many foods and drinks attract or repel mosquitoes.
Some, like garlic, are promoted under the logic that the strong smell will help mask the smell itself, acting as a kind of olfactory camouflage.
On the contrary, it is stated that salty or sweet foods have the opposite effect by producing compounds that make us more attractive to mosquitoes.
One study, admittedly conducted on only 14 people, found that mosquitoes were more likely to land on a person after they had drunk some beer.
Even beer might not be a safe option. One study, admittedly done with only 14 people, found that mosquitoes were more likely to land on a person after they had drunk.
But the real evidence for these works is contradictory. Multiple studies have failed to demonstrate that what we eat or drink influences mosquitoes or their findings are very limited.
Dr. Jones said that given the unreliable nature of using food or drink to ward off mosquitoes, it is best for people to stick to standard repellents.
“It is much better to use methods that have been shown through rigorous scientific testing to provide a high level of protection against bites,” he said.
“There are several insect repellent compounds that are effective for many hours against a variety of mosquito species and can be used safely by both adults and children.”
It could, just a little bit, be all in your head.
Another factor to consider in the mosquito preference debate is that you could be the problem.
Dr. Jones explained that some people have worse reactions to mosquito bites than others.
This can make your bites look worse, itchier, bigger, and more painful, so it can even make you look like you’ve been bitten more than another person with the same number of bites.
So what can I do to try to avoid becoming a mosquito buffet?
Tips to avoid mosquito bites include wearing long-sleeved clothing and pants, using insect repellent, keeping accommodation windows closed or using mosquito nets, and sleeping under a mosquito net.
People should be especially careful in the early morning and early evening, as this is when mosquitoes are most active.