The fact that blood-sucking little creatures approach people very selectively is an indisputable fact. To be convinced of this, it is enough to get out into nature with company in warm weather. Some mosquitoes will begin to attack in the very first minutes, while others will show enviable indifference, limiting themselves to a few bites. “You are probably more appetizing!” - the lucky “nibbled” ones tease. And many do not even suspect that there is a scientific basis for such selectivity of mosquitoes.
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Taste and color
There are at least some serious studies confirming that mosquitoes (females, since they are the ones who bite) like blood type 0 (I) more than A (II), B (III) and AB (IV).
They fly by smell, since each blood type releases certain chemicals. The “first-graders” suffer first of all, but the rest also benefit, since they also have something attractive to “nosed gourmets.” What exactly? To begin with, we note that mosquitoes can drink the blood of almost all animals, however, they prefer ours. Firstly, humans have thinner skin. Secondly, there are quite a lot of people, which guarantees an uninterrupted source of food for blood-sucking insects. Thirdly, they are attracted by the smells of lactic acid, ammonia, acetone, some carboxylic acids and other substances, which are more abundant in the human smell than in animals. Such compounds are formed as a result of biochemical reactions, which occur especially intensively during physical activity. And if people don’t like the smell of other people’s sweat, mosquitoes simply adore it. This is for them as it is for us “shish kebab with cognac”. By the way, alcohol also counts - a drunk person runs the risk of being bitten more than a sober person.
And finally, there is one more component that attracts mosquitoes - substances secreted by skin microflora. Its bacterial composition is individual for each person, but mosquitoes like bacteria of the genera Bacillus, Brevibacterium, Corynebacteria and Staphylococcus. It is possible that someday it will be possible to find out which microorganisms, on the contrary, repel bloodsuckers, and repellents made from “natural raw materials” will appear in stores.
Why do mosquitoes bite?
Skin bacteria
Other research suggests that specific types of bacteria that live on our skin influence our attractiveness to mosquitoes. In a 2011 study, experts found that the presence of large numbers of several types of bacteria on the skin fascinates mosquitoes.
Surprisingly, places where there is less accumulation of bacteria practically do not attract mosquitoes. This helps explain why these insects are so fond of biting our ankles and feet, since this is where the largest amount of bacteria tends to accumulate.
Beer
Just one half-liter bottle of beer and you have already become a potential victim of mosquitoes. However, while the researchers suspected it was due to increased ethanol excretion through sweat or increased body temperature, none of these factors directly correlated with alcohol consumption.
Treatment of mosquito bites: 13 natural and effective remedies
Thus, it is still a mystery to scientists today why people who have consumed alcohol are more attractive to mosquitoes than non-drinkers.
Pregnancy
Numerous studies have shown that pregnant women are twice as likely to be attacked by mosquitoes, all due to the confluence of two factors:
they exhale 21 percent more carbon dioxide and their overall body temperature is slightly higher.
Clothes color
It may seem absurd, but mosquitoes use sight (along with smell) to locate their prey, so if you wear colors like black, navy blue or red, the insect will find you faster.
This conclusion was reached by James Day, a medical entomologist at Florida State University.
Genetics
In general, genetic factors are responsible 85 percent of the time for our attractiveness to mosquitoes, regardless of whether we are talking about blood type, metabolism, or some other factor. Unfortunately, today scientists do not have the opportunity to fully analyze these factors.
Natural repellents
Many experts are currently busy studying the reasons why some people repel mosquitoes completely in the hope of creating the next generation of insect repellents.
By using chromatography to detect the corresponding substances released by these people, scientists from UK's Rothamsted Research lab in the UK found that such people are carriers of natural repellers, which tend to secrete several substances that mosquitoes do not like at all. .
As a result, if these substances are added to advanced mosquito sprays, even people with the first blood type, sports enthusiasts, pregnant women, as well as supporters of dark colors in clothing will be able to get rid of these annoying insects forever.
Flying laboratory
Every year, mosquitoes kill about 2 million people around the world, mostly in hot countries where there are problems with medical care.
The bite itself, of course, is not dangerous, but insects carry many diseases, including malaria, dengue fever and others. Fortunately, mosquitoes cannot infect humans with some very dangerous viruses such as HIV. Even if they first bite an infected person and then a healthy one, there will be no consequences - such viruses do not survive in the body of these insects. The COVID-19 pathogen is also not transmitted by mosquitoes (at first there was panic, but scientists are categorical - this is impossible). However, mosquitoes are “selective” when it comes to transmitting different viruses. For example, they can infect people with the Zika virus, but not with the Ebola virus. Why? The thing is that the mosquito’s body works like a complex distillation cube, and even with some nuances. When a mosquito bites an infected person, blood flows into the insect's intestines (yes, it has one). Here the virus must first infect the lining cells, but this is not easy. Next, it (if it survives) must enter the salivary glands. And not every infection is able to successfully travel this path.
How do mosquitoes find their prey?
Mosquitoes find people by our movements, by the heat we emit and by our smell. When a mosquito flies past our ear, we hear a high-pitched ringing buzzing sound, the sound of the mosquito's tiny wings working.
Scientists believe that buzzing attracts members of the opposite sex, but it is especially tiring for us at night, when the heat makes it difficult to sleep. According to scientists, mosquitoes most often go out on their bloody hunt at night. With dawn, the warring parties can calm down and sleep, instead of exchanging deadly blows.
Who do mosquitoes bite more often?
Although we don’t really like the idea of being eaten alive on warm summer evenings, we must still say that humans are by no means the mosquito’s favorite meal. Human blood is low in the amino acid isoleucine, which is essential for egg formation. Therefore, buffalo or rat blood is preferable for mosquitoes. But humans have displaced animals from their usual habitats, so mosquitoes have to depend on us. We provide them with shelter (unnecessary bottles and cans, old clothes) and food (our own warm blood). We are not buffaloes, but the situation obliges us...
Bite process
The process of biting
Having made a soft landing on the surface of human skin, the mosquito lightly taps it with its proboscis, as if knocking on a door. A mosquito's proboscis looks more like a snout. Then, raising its hairy lip, the mosquito carefully thrusts its stiletto, which is hollow inside, into the skin. With its surgical instrument, the mosquito probes small veins and capillaries in search of blood. The process of saturating a mosquito with blood lasts less than a minute.
Before it starts sucking blood through a straw, the mosquito injects a special substance into the blood that prevents it from clotting (so that the blood does not clot while the mosquito is sucking it). A mosquito can ingest four times its own weight in blood. At the end of the bloody mosquito dinner, his stomach is incredibly swollen. If you watch a female eating lunch on your hand, then by the end of lunch the blood will show through the wall of the mosquito’s stomach. According to one zoologist, a blood-sucking mosquito looks like a red ball on a Christmas tree.
Interesting: Why does smoke “calm” bees?
Fun fact: Only female mosquitoes bite.
Dependence of the number of bites on blood composition
To stop blood-sucking insects from biting, people use a variety of folk remedies. And especially popular are herbs that are planted on the plot or window sills. These properties of spices can be used by eating them. After all, spices change the composition of sweat. Therefore, insects do not approach those who eat cumin, turmeric and basil. To achieve the required result, it is necessary to consume spices at certain intervals.
The situation is similar with people who suffer from cancer. Once doctors detect cancer cells, they begin chemotherapy. Medications affect the composition of sweat. Blood counts are also taken into account. Pests do not react to people who have medications in their bodies. If people with cancer say, squeaking mosquitoes don’t bite me, then they are not lying. After all, their bodies contain a variety of chemical components. The exception to the rule is people who have leukemia. Some mosquitoes choose only leukemia patients.
Insects attack people who have alcohol in their bodies. Some mosquitoes have adapted to ethyl alcohol.
How can a person be infected?
These individuals cannot be called harmless, because they are carriers of serious diseases, which include:
- Malaria.
- Encephalitis.
- Yellow fever.
- Tularemia.
- Dengue fever.
- Lymphatic filariasis.
Previously, diseases were common only in Asia and Africa, but now this problem affects all countries. To eliminate this problem, a special program “World Mosquito Program” was created.
It is aimed at making these individuals absolutely harmless; for this they are infected with the Wolbachia bacterium, which destroys any infection and prevents it from developing.
Blood type
Chemicals secreted by humans through sweat allow insects to determine the blood type of their prey. Scientists have found that the first group is the most attractive to mosquitoes, the third and fourth are tied for second place, and the second is the least desirable.
Fifteen percent of the world's population is invisible to mosquitoes. Their biological secretions do not allow insects to determine the blood type and they will not be able to specifically attack such a person. They will only be able to drink the blood of the “invisibles” by accident.
Mosquito sense of smell
Blood-sucking insects use their olfactory organ to search for prey and track repellents. This property is used by manufacturing companies that develop and produce insecticidal preparations and repellents. Modern sprays and aerosols eliminate the smell of human sweat and help relieve swelling. Therefore, pests bite some people hard, but do not notice people standing nearby. Some people use their favorite scented sanitary product to repel mosquitoes. This is another reason why mosquitoes are most likely to attack people who don't shower regularly.
Blood myths and reality
Experts who are interested in why squeaking mosquitoes do not bite everyone note that attacks depend on blood type. But this theory is not confirmed by any serious facts. To make it easier to determine who blood-sucking mosquitoes like to bite, you need to consider some points:
- What foods and substances were present in the diet.
- Human body temperature.
- Shade of clothing. Some scientists have put forward theories about what color mosquitoes don't like.
- Number of people.
- Temperature and humidity level. This is the main reason why experts track these indicators.
- Body parameters. It happens that blood-sucking pests bite more often a person from the third than from the 1st and the other.
- Presence of medications and chemicals in the body. It doesn't matter where they come from.
- Powders and chemicals used for cleaning and washing clothes.
- The presence of perfume or cologne.
If you study the data presented by doctors and researchers, it is easier to understand why mosquitoes do not bite certain people.
You are pregnant
Image: Anastasiia Chepinska / Unsplash.
One study conducted in The Gambia identified R. Dobson. Mosquitoes prefer pregnant women / BNJ that the local gnats are twice as active in their interest in pregnant women.
The researchers suggested that this was due to an increase in the amount of carbon dioxide they exhaled. Also, pregnant women had an increase in body temperature of approximately 0.7 °C. And both of these factors affected visibility to mosquitoes.
In general, the results of this experiment should have been rechecked, because only 72 subjects took part in it. But there is some truth here.
Solution. It never hurts to take a pregnancy test.
You don't wash your feet
Image: Huỳnh Tấn Hậu / Unsplash.com
One experiment NO Verhulst. Composition of Human Skin Microbiota Affects Attractiveness to Malaria Mosquitoes / PLoS One 2011 showed a strong correlation between the number of bacteria living on the skin and mosquitoes' interest in that area. The largest colonies of microorganisms are located on people's ankles and feet, so bloodsuckers look at your bare legs with great interest.
Solution. Wash your feet. Do not stick them out from under the blanket.
Why do mosquitoes drink blood?
As mentioned earlier, the female individual needs blood only for the reason that she needs useful substances in order to lay offspring, namely amino acids, which serve as building materials for eggs.
In the case when the female does not receive blood for saturation, she cannot lay eggs in large quantities, so, with saturation, the number of eggs in a clutch reaches 100, without saturation the maximum can be 10 eggs, but most often, such a clutch contains only 1 egg.
You sweat and have an elevated body temperature
Image: un‑perfekt / Pixabay
Strictly speaking, not only people who exercise a lot, but also anyone who sweats excessively are under the close attention of mosquitoes. Uric acid and ammonia present in sweat signal JI Raji. Aedes aegypti Mosquitoes Detect Acidic Volatiles Found in Human Odor Using the IR8a Pathway / Current Biology I'm going to fly off to see what's delicious.
It may seem that it is enough to spray with deodorant or cologne to fight off the smell of sweat. But according to This Is Why Mosquitoes Target Some People Way More Than Others/Self by Dr. Gary Goldenberg, medical director of the department of dermatology at the Icahn School of Medicine, some perfumes, on the contrary, only attract bloodsuckers more strongly. Mosquitoes find sweet scents especially attractive.
Solution. To combat excessive sweating, or hyperhidrosis, you need to make an appointment with a dermatologist. In addition, you just need to wash yourself more often.
