Why do mosquitoes bite some people more than others?
- asks Allison from Austin
Meredith Knight • September 10, 2007
![Credit: [Oxbow Park Naturalization Project].](https://scienceline.org/wp-content/uploads/2007/09/mosquito.jpg)
Credit: [Oxbow Park Naturalization Project].
Every summer, they come. They sneak through the windows and ravage your ankles; they find the one spot on your left shoulder that didn’t get drenched in a layer of DEET (God bless you, Deep Woods Off!) and gnaw, chomp, and suck away.
From May to September, many of us – covered in scars and bloody scabs, the remnants of these bites now gone bad – live side-by-side with people who, despite living in the same house and even sleeping in the same bed, are seemingly less vulnerable to the vicious six-legged predators. It turns out, a mosquito’s snacking preference for one person over another is not just a curious annoyance, it’s also a medical concern: Since malaria and other diseases are transmitted by bites, people who get bitten a lot are more likely to become ill. Because of this, researchers are working to find the mechanisms in mosquitoes that cause them to sniff out you, and not your neighbor.
Scientists have identified several proteins found in mosquitoes’ antennae and heads that latch on to chemical markers, or odorants, emitted from our skin. These markers are produced by the natural processes of our bodies and, like neon signs, they let the mosquitoes’ smell center know you’re around (though the process that then guides them to you is not well understood). Flies and mosquitoes share a number of the same genes that dictate production of these odorant-binding proteins, which have specific sites that will catch or bind with certain chemicals in the air. Some scientists suggest that certain characteristics attract mosquitoes, thereby leading us to have more bites than others. Some of the top candidates: the amount of carbon dioxide in the breath, pregnancy, body temperature, alcohol and odorant markers based on blood type.
Blood-type markers are chemicals released by people of a specific blood type – so if someone with AB blood emitted a marker, it would be different than that released by B. One study found persons with Type O blood suffered more mosquito landings because of the odorant markers they emit than any other blood type, making their juices a hot commodity for blood banks, as well as Asian Tiger Mosquitoes, which carry West Nile Virus. Not only were Type O’s more likely to be landed on, but the study found that for any blood type, people who secreted a chemical marker about their blood type through their skin (both blood type and secretor status are determined by genes) were bitten much more than non-secretors; 24 percent in the case of the Type O’s. Other researchers estimate about 15 percent of the population, based on their genes, don’t emit chemical markers of their blood type through their skin and saliva, so something else has to be calling the mosquitoes to them.
Pregnancy seems to be a big winner for mosquito attraction, probably because mothers-to-be exhale 21 percent more carbon dioxide (quite a turn-on to the six-legged species) and are on average 1.26 degrees Fahrenheit warmer around the belly than their non-pregnant counterparts, due to the temperature of amniotic fluid. Also, having just 12 ounces of beer increases your mosquito appeal, possibly because of the increase in body temperature it causes or because skin markers change when metabolizing cocktails – unfortunate since outdoor drinking is a highlight of summer anywhere.
One researcher suggested smell is unimportant, and what really matters to the mosquito currently chomping on your toe is not the smells you’re giving off, rather it’s finishing her meal without being swatted away. Because of this, she’s better off attacking “less defensive” animals, rather than more defensive, and so is evolutionarily predisposed to biting lazy or incapacitated prey (reference drinking above).
Infectious disease experts are anxious to solve the mosquito preference puzzle so they can design repellants tailored to vulnerable people, which would either block an individual’s smell signatures or disarm a mosquito’s scent receptors. Unfortunately, a specific answer to your skin-piercing question continues to itch away at scientists, and I suggest stocking up on bug repellant in the meantime.
409 Comments
thank you for the article.now i can answer to some dumb people when they say i get bit by mosquitoes because of my body smell.i get so agravated!!!
I just absolutely KNEW that frequency of bites had to do with blood type. I am type O and am ALWAYS getting eaten alive by mosquitos! Many of my friends that are type A NEVER get bitten, even when a mosquito lands on them!
Erm… I’m an O and I never get bitten!!
My blood type is a+ and I am always getting bitten. I think it’s because I am so sweet. LOL
I have a real problem with mosquitoes biting at my bag, is it possible my bag emits an odor that attracts mosquitoes?
LOL this thread is messed. Mosquitoes bite people to live and feed their young, the numbers mean nothing and I would have to go with the chaos theory, in that someone has to be bit more than another and someone has to be bit less, otherwise the world would explode without randomness, or chaos.
Wanna learn something that pertains to everything, check out chaos theory. Stats are pointless.
Interesting, but my family totally blows the blood type theory. I have a daughter who is B+ who absolutely gets eaten alive and one who is A+ with a pretty strong attreaction. The rest of us who are A+ and O+ use the first two as our repellent.
Last year i went on holiday, my brother aged 10 and my son aged 4 shared the same room my brother got bitten loads with repellent on and yet my son didn’t get one bite we used repellent on him the first couple of days, but after that he didn’t have any on as they didn’t seem to like him and he still didn’t get bitten. Im just intriged to know why???
Always knew it must be linked to blood type, not sure on the O type though, Im A- and always get bitten alive while no-one else does!!???
Thank you for this article. now i have an answer to why mosquitoes bite me all the time instead of the other people in the same room as me. it’s only because of my rich thick blood type! and because of bodyly secretions that i give off. and my smell, and a whole lot of other things. thanks!
how about this…when i get bit by mosquitoes, which not only seems to be more than everyone i know, i get bitten in quick clusters. i don’t just get one generic bite here and there. i will get bit in repeated succession in a big cluster of sometimes four or five bites in a small area. no matter where i go, this holds true.
i am type O and i never get bit. i don’t think i’m buying the blood type theory. there are posts here of people all over the blood type spectrum and their experiences are just as widely ranged.
OMGGGGGG!!!!!!!!!!!!!!!!!
I GET BITTEN BY mosquito all the time, and i have no idea what my blood type is.
I am type O and get eaten alive even with repellant on. I also have a blood disease called ITP, and I wonder if they like me because my blood does not clot normally.
Interesting…but the photo above the article is not that of a mosquito but a (harmless) crane fly. it would be hard to bite someone, regardless of blood type, without a nice long proboscis (nasty bitey part).
I am blood type B+ and have been attacked by mosquitoes continuously all of my 70 plus years. I have applied many different types of repellants but as of yet have not found one that works well. I have attracted them in the American continent all areas and also in Asia. I am resigned to being bit as there isn’t much I can do about it, hopefully sience will discover the reason and develope a repellant.
This information I just read is right. I have never been bitten by mosquitoes But now i have been drinking a couple of beers in the afternoon and I go out and i get bitten within minutes at least in four different places uncles ,elbows and ,knees .When I drank red wine it never happen
I am AB+ blood type and Im bitten by mosquitos ALL THE TIME! Im just so sick of it!! Even the repellants dont help me! Its terrible.
However, besides the blood type, the article states that the body warmth and alcohoc composition are also factors of attraction! :(
Thank you for the article!
blood type? what about body temperature? I have a normal body temporature of 96.3sih rather then 98.6 and i never seem to get bit. might not this be the major factor? warmer people get bit and cooler people don’t….Possible?
One thing the article mentioned is that not everyone emits the scent of their blood type. Which would explain why some people with a certain blood type get bitten and some don’t – they don’t excrete the scent.
I get bitten constantly. My mom does too. On a recent vacation to a lake house I was outside just as frequently as 2 friends and my husband (who threatened to put me in a bubble!) – we all drank the same amount, wore bug spray, and were even using the same shampoo and soap. I went in every night covered in bites, while everyone else was untouched; including, luckily, my son.
It is obnoxious. We just killed one in the house – it bit me 5 times before we could get it. Grrr…
Body temp is interesting – I have a low body temperature of around 96.7, and I don’t remember bites being much of a problem when I was pregnant.
Thanks for the article!
I live in a hot country and being constantly bitten is getting me down quite a lot.
I now wear repellent every day and carry it with me. When i arrived 3 months ago i ended up scratching so much that the bumps and itching came up all over my arms and legs and stomach. It seemed like an allergic reaction to the bites but the doctor didn’t seem sure what had caused it. She said it was a food allergy or an allergic reaction to the bites. I think it was the latter.
I have A type blood so that blood theory seems a bit off to me. My partner doesn’t get bitten very often, just now and then. Also my daughter gets quite a lot but not my son. Is it the female hormones that maybe attract them more or what?? The biggest annoyance is that i’ve been wearing trousers lately and get bitten on my legs so how the heck are they getting up my legs. I despise mosquitos. Why can’t they become extinct??
I’m type O and used to get bitten a lot. Now that i’m older, i don’t get bitten as much. As it’s stated, 15 percent don’t emit the blood marker. But from what i’ve learnt, mosquitos are attracted to CO2 as well. So people that never get bit either don’t emit much CO2 or a blood marker or are move enough to keep them off.
It states that type O are bitten more, but that could be the marker is more familiar as there’s more O around and is the oldest type.
People that aren’t O but get bitten a lot, it could be you give off more CO2, emitted a higher blood marker or just really unlucky. I think i get bitten less because i weigh a lot more and my diet’s changed.
My wife and myself plus my sister in law and her husband have just returned from playa del carmen in Mexico. My wife and her sister are twins and have the same blood group as myself (A+). I have over 40 bites and my sister in law in excess of 30, my wife had NONE and my BIL 3 which were barely noticeable. In terms of alcohol my BIL drinks more than all of us and is blood group (O).
I can’t comment on carbon dioxide levels but an certainly say neither my wife or SIl are pregnant … in short i’m none teh wiser just very itchy
I live in Thailand and am relatively unaffected by mosquitoes – I notice though that most of my friends who are, take ineffective precautions. They claim all sorts of reasons and then go out in the evening in short sleeved shirts and no socks.
They become obsessed with ridding a room of mosquitoes and then sleep without bedsheets……
odorant marker emmited from the blood type..interesting..i always wondering why my mother’s always gets bitten instead of my father.. my mom always says that she has a sweeter blood than my father cause she’s the only one gets bitten.. but based on temperature it’s kind of opposite cause my father’s body temperature is higher than my mother ..
I am blood type AB+ and prior to having a kidney transplant didn’t have any major issues with mosquitoes. Since the transplant and the immunosuppresion medication i take, I now have a huge problem with being bitten and also how much they itch. The itching becomes almost unbearable and as someone else commented I now get bitten in clusters of about 5 or 6 bites at a time. It would appear that mosquitoes are definitely attracted/deterred by different odors, otherwise repellents wouldn’t work. I know that since the transplant I have had some hormonal changes so I’m guessing their attraction to some and not others could be to do with hormone’s and their affect on our bodies
my experience is different then anyone else!!!
infrared radiation of body is more likely. I don’t know if you noticed but they bite rite on the veins. closer the surface. sounds more logical as well. other reason they fly closer to ear lopes at night. one more observation is they use ear drum as speaker and radar they bounce their wing noise find their way like bats.
anyone to test these?
let me know. email haluk@bosspacific.com.au
I have a+ blood so does my son. I never get bitten, my son gets covered from head to toe in bites and where there are no bites there are scars from last years bites, he is constantly uncomfortable and itchy. I completely disagree with the blood type theory. I agree with the explanation that we are all bitten, but only some of us react negatively. I beleive those that are already predispositioned to things like asthma eczma and allergies are more prone to have an overeactive immune system that may cause these small bites to become irritated.
Over the last two nights my partner and I have been unidated with the pesty Mozzies, my partner who is A blood type has been bited 13 times in the last two nights and I being O+ have no had not one single bite. So that blows the theory about blood group O is bited often than other’s?
So, what are scientists waiting for to find out
what the mysterious secreted scent is that attracts
these nuisance bugs?
This isn’t rocket science!
I think this is all very interesting – because my personal experiences are the opposite to the article. I am 30 and British and now live in South China where mosquitos are rife. I am O- blood type, I drink alcohol, and eat cheese…but I never get bitten (touch wood). My poor Chinese girlfriend on the other hand is A+, doesn’t drink alcohol or eat cheese but gets bitten all the time – to the point she is left with swellings and bruises. More research is required here I think. And yes, you would think this would be straight forward enough for scientists…
oh by the way serena, my girlfriend has no other allergies or asthma etc but still gets bad seriously bad reactions to the bites…
Mmmm…. I don’t think it has anything to do with blood type. I am Asian with AB+ blood type and I get eaten alive!! If I am with a group of 10 people, the mosquitoes will still find me! More research is needed. I usually don’t go out after dawn….
Since I started to take Simvastin tablets 2 years ago to reduce cholestrol I notice that in the aerly part of the year March-may I get bitten regularly and generally have about 3 to 5 bites on the go at any one time.
before I took these tables I rarely got bitten and generally once the damp season is over by June I am okay.
I really don’t know what to do to stop them,even when I tuck my socks into my trousers if I go out into the garden they seem to get up my trousers.
I was biten all over yesterday.
The strange is, when I was in Asia, I was never bitten and now I’m back in Europe, the second day I had like 150 bites.
why is it mosquitoes more attracted to type O blood group people? any scientific evidence please?
Hi I am a 57yr old woman and as for as long as I can remember I have been been bitten by mosq. I am sitting here with numerous bites and I wasn’t outside!! We have a whole house fan and opened the windows(screens) and I got bitten!! I am type 0+ and I also have ITP.
My husband never gets bitten…I found out I am also allergic to mosq. so the itch is unbearable!! I am frustrated to say the least.
I agree with the temperature idea in this article. I have such a low body temperature I hate air conditioners. I can’t remember the last time I was bitten, though people around me seem to be magnets for mosquitoes.
Didn’t really care til I went to the beach with my girlfriend and wanted to sleep under the stars with a comfortor and pillows in the bed of my truck. No bug spray was used because we didn’t think of it.
I got destroyed by mosquitos! I probably got bit 50-75 times and my girlfriend got bit maybe twice. While I was wrapped up like a mummy sweating, she was next to me with her leg out of the covers to cool off. She thought I was crazy til she saw the welps the next day.
we’re both A+
omg I am A+ and I get eaten alive. I just walked out the door just now and got bit six times within less than 10mins. My husband has O+ and he never get’s bit. My legs and arms look like I was stung by a bee instead of a musquito. I hate them so much.
I’m a professional statistician and I feel a need to clear some things up.
There is a probably a correlation between having type O blood type and getting more mosquito bytes, but as I’m sure you’ve all heard, correlation does not equal causation. This is an example of confounding with odorant markers, which are associated with both the outcome (more bites) and the predictor (blood type) and differentially distributed between the levels of predictor. Though having type O blood may not in and of itself be reason for a mosquito to choose one person over another, type O blood *is* more often observed in the “secretors” that mosquitos prefer.
I’d hypothesize that in an experiment where odorant levels are controlled, the relationship between blood type and bite predisposition would vanish. However, you can say that on a population-wide level, knowing a person has type O blood makes them more likely to be a mosquito magnet, inasmuch as it makes them more likely to have the genes for giving off a mosquito-friendly scent.
I am type O+ and was only outside for an hour today and got bitten 13 times. Mosquitoes just love me and it is annoying. Every year I get so many scars from these nasty blood suckers because I itch them so bad. I think it is because my blood type. Everyone I know only get bitten every once and a while and none of them have type O blood like me.
Since becoming a raw food vegan mosquitoes don’t touch me like they did in the past, has there been any studies on the correlation between mosquito biting & blood purity or cleanliness??
ugh,as im reading this both of my feet are swelling b/c i got bit on the toes and around the house too!… does that mean im allergic???
the last few weekends we’ve had outdoor dinners w friends. I’ve been bitten over a dozen times each night. The three others are usually not bitten at all, or may have one or two. Blood type or something else… this has been happening to me for years.
Hi, I get bitten all the time and very badly. Abroad or at home. The only repellent that I have found good is avon skin so fresh – woodland fresh. I have used it in USA, UAE and all over the world. So long as I am wearing it head to toe I am ok!! With out it I have been admitted to hospital as I react very badly!!! I only hope it continues to work for me!!
I think that a mosquitoes only bite you when you are in the shade, if you are in the sun they can not see you beacuse you blend in with the heated suroundings.
I think they see heat, like in the movie preditor, he did not see Arnold as a human but as heat while in a shaded forrest but as soon as Arnold covered himself with the cool wet mud then the preditor could no longer see him.
I don’t know for sure but this is my think on how they pick you out and heat among a cool back drop says food to them.
Well, anyone notice that the insect used for the picture on this article is actually a Mayfly? I get bit a lot! can’t a gene specialist create a strain of Mosquitos that all of the sudden mutate and have no wings after several generations? Seems like beter use of gene studies, ridding the planet of Mosquitos would solve a lot of infectious diseases.
I went to Southern Maryland last summer and I got bitten so bad. I had about 20 bites on each leg and a whole lot of random ones all over my body. I just came back from Cape May, NJ and I am bit up again. Not quite as bad but I have about 7 or so on my legs and ankles, some around my neck and ears and some other random ones. I am not sure of my blood type but I wish I knew why these things bite the hell out of me. My boyfriend was with me at both places, doesn’t even put bug spray on and only gets like 1 or 2 bites total. Here I am scratching like crazy. I don’t understand and I am honestly quite sick of these damn bugs biting me so much. I wish I knew what the reason was. I don’t wear perfume when I’m outside in the spring or summer cuz that makes it worse. I was told to swallow a matchhead before going outdoors in areas I might get bitten.
My husband and I can be sleeping on the same bed or be in the same vecinity as a mosquito and they never bite him: They feast on me! I jokingly tell him its my sweet blood they’re after. I have O+ blood, I’m not sure what my husband has.
All this thing about blood group and CO2 etc is bull crap . Just read the comments and you can tell – these are not common factors among the people who get bitten.
If you have been doing bad things, God sends mosquitos to leech you. Thats right – its a punishment plain and simple.
If not , you are spared – how difficult is that to understand ?
Long story short – do good deeds that will please God, and he will in time direct the mosquitoes to the bad guys.