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
I am a white make 53 years old, my sister is 1 year younger, since we were small children we have not been bothered by mosquitos, my father was also not bothered by them durnig his life. One intersting note is that all three of us have/had blood type O negetive, while my mother who had A (I think) blood was constantly being eaten up by them, this isn’t just that they don’t bother me much, I mean that they don’t bite me at all, maybe twice in 3 or 4 years.
I really don’t get it…I am an 0- i will be the first person to get bit all the time but my brother in law is an A and he NEVER EVER gets bit..and when he does the 1 mosquito that bit him ends up just flying away after 1 sip! They just keep suckin away on me until I have a bit the size of a half doller coin of course. There really bad can anybody help me with any suggestions..I put on OFF sport for waterproof and sweat proof and that really doesn’t work eather….
I’m a redhead with fair skin. I’m also a bit heavy. Mosquitos ALWAYS target me. As soon as it is dusk – I’m toast! Right now I have about 20 bites from working in the yard. It’s the most I have ever had and it’s sooo itchy!
I am Blood type O+ and I seldom get bit. If I get 5 a summer that is a lot.
im O- and never get bitten. they will land on me and then fly to the next person. i dont even own a can of mosquito spray. i wonder if it has more to do with what foods we eat and how our bodies digest it? you are what you eat right? mabe some blood is less desireable to them.
I’m 30, pregnant and have type A+ blood. Ever since I was a little kid, I’ve been the only one who ever gets bothered by mosquitos and, even more horribly, no-see-ums. I was pregnant with my daughter in the summer of 2007 and counted over 60 no-see-um bites on my left leg alone–and I also have immune system problems…so these bites were ten times worse than the two my son had and the one my husband had. Ugh, I hate bugs and the itching and scratching and burning feeling they leave me with. I have scars ALL OVER my body from childhood and adulthood from scratching the bites until they bled and then scratching at those because they still itched. :((((( HELP!
Im A+ blood i get bit so much right now i have 57 i counted the most ive had is 88 i use bug spray but it dosent work and this happens every year since i remember im only 15 so hopfully u can find a way 2 stop this
quoting Sasha from July 6, >>I’m the same way they will land on me and kind of sniff around and then fly off, occasionaly one will try to bite and sort of gets stuck, I’ll reach down and wipe her away, never get any kind of bump or mark from it.
I am blood type A, I get eaten alive by mosquitos whereever I go. In the Caribbean I got pretty large watery blisters and intense itching. I will never go back there. I had on repellant, mosquito netting over the bed, tooks loads of the vitamin Thiamine, burned mosquito coils under the bed and on both nightstands and they still bit me. I just got back from Redding, CA and they aren’t nice ones up there either. I’m still itching a week after I was biten 9 times. I got watery blisters from those bites also but only half as bad as Antigua, St. Vincent and Bequia. Eash island seemed to get worse and it was actually making me sick. It wasn’t even mosquito season! I have found that if I can apply Witch Hazel on a cotton ball as soon as I am bitten that it helps a great deal.
By the way, my boyfriend is an “O”. They hardly touched him and if they did he had only minor irritation that didn’t last more than an hour or two. He had no repellant on at any time to try to keep them from me but it did not work at all.
I’m just rereading these things and other than the few crazies it seems that you are all saying that the Positive blood type(both O and A) people are being eaten, as opposed to the Negatives. Can that be the link?
Such sad posts. I’m B+, get eaten alive and in clusters if I spend more than two minutes in my front yard. No one else is affected. Other family members = three O+. Years ago a landscaper told me to take garlic capsules. They work wonderfully. Just started taking them for this season and can’t wait for the effect to kick-in. Scratching now,
Too bad there is no easy explanation. I have O- blood, so that theory is fun to entertain, but for half my life I was not at all bothered by mosquitoes, now I am their favorite food source. I spent the day at Sunrise in Mt Rainier National park yesterday and was covered with bites that, again, swell and welt, my hands and toes were swollen. They bite regardless of what I put on or wear. The allergic reaction I get is a bit frightening, I actually got a cold shiver after one set of bites. I am worried about what is happening, on one camping trip I had so many bites that would not come out of the camper and took antihistamines to counter the hives and chills. This used to never happen, and I usually camp in a tent, and have for years. It is like thing flipped a switch in my and I have become bait. I was not drinking anything but water, my diet (good, healthy) has not changed. I am carrying a bit more weight than I did as a teen or a twenty-something, and after 2 pregnancies I have not the same weight as I once did. There was a difference after having 2 children in how many mosquito bites I got (lots more). But now, I am in the middle of the mosquito’s radar zone.
I am also A- and always get bitten more than any of my o Positive relatives, More study needs to be done!!!!!!!!!!
A positive and I almost NEVER get bitten.
There must be something to this blood type stuff.
I live in the Philipines with my brother. He is blood type O the same as me.
We eat the same food and drink the same types of alcohol.
I have never been bitten in my life but my brother is a target. I believe there is something in my blood which deters the mosquitos. I have watched one land on me and immediately take off probably heading towards my brother!!
question for Elizabeeth, you said that the first half of your life you were never bitten, now you are their favorite food, at what age did this change, and were you pregnate? my sister’s imunity changed with her first pregnancy.
I am blood type A+ and get bitten really bad, the only thing that somewhat helps me is Avons “skin-so-soft” and even that wears off after a while. Ny husband’s type is O- and he rarely gets a bite. These seem two be two ends of the spectrum that mosquitoes either attack or dont. I guess theres no set pattern
Mosquitoes used to bother me tremendously. The bites produced the standard welts, and itched like crazy.
After spending about 15 years as a Conservation Officer in Michigan’s Upper Peninsula – with LOTS of mosquito bites – I realized that I no longer got any bites. For the rest of my career, I was bite free.
Even now, 12 years after retirement, I have an immunity. They still buzz around me. On occasion, I will feel a very slight stinging sensation, as one starts to bite me. They never complete their meal, but fly off after just starting to bite.
I bet people who get laid more get bit less. Mosquitoes can feel that tension
Hot blooded O+ type scratching the heck out of myself at the moment, looking for a dang cure. Can I deposit my blood at a blood bank and ask for a different currency? I don’t care if the exchange rate kills me, this is insane! I don
if you have the o blood type the only reason wny they come after you is becuse thay cant resist is because it tastes so good to them.
this kind of explains a lot. im leaning more towards the chaos theory though. i believe randomness is essential to order.
I just wondered is it because o type blood can be given to most blood types and is a common to all. I am O possitive and I am alway bitten and even by the irish flys from end of augst, Help needed.
my whole family is type o blood, but for some reason i always get bitten the most and have a minimum of 30 bug bites on me at all times during the summer. they usually center around my ankles and feet, i guess i just happened to be the one who got the most delicious combination of genes in the family…
I have always thought something to do with blood. I am A-, so was my Dad; rest of family +. He and I always bitten, others not. My theory has been that is to with the negative bit rather than whether A, AB, O etc. Not only do I always get bitten, but I am allergic to the bites and always get infection, cellulitis, allergic reaction bordering on anaphalaxis – last time ended up on a drip for 24 hours!
I’m blood type A and get absolutely chewed on; my wife is an O and the little buggers don’t even seem to know she’s around.
I was under the impression the heat signature you put out affects how mosquito’s “see” you.
She’s ALWAYS cold, but I put out a tonne of BTU’s.
The house could be on fire and she’d be putting on a sweater – I’m happy in a -30 blizzard.
But then there’s no mosquito’s around then.
My husband is type O and the mosquitos don’t pay any attention to him. They go straight for me, type A. Could it be the secretor? I should get that checked.
I am blood type O and get bitten like crazy. I just had to speak with someone out in the yard, I was immediately attacked by mosquitoes and ended up cutting our conversation short because of the mosquitoes. The man I was talking with did not get bitten. Now have about 30 bites all over from just 15 minutes outside! I put on repellent in the morning but don’t always remember to reapply it until after I am attacked. I was once told that taking B vitamins would stop them from biting you, but I tried it, and actually I still take B vitamins and still get bitten like crazy. I am interested in the garlic capsules. I already take one garlic capsule a day, if I took more I wonder if it would help? Also would it have to be non-de-odorized garlic?
i kno how yall feel. i have nooo idea what blood type i am but all i kno is that everyday, i HAVE to get bitten by a freakin mosquito. my problem is i walk a lot but, just when i get to my house, i get bit.i wear shorts that go to my knees so how do the dang pests get up to my thighs? heres my solution,not much help but it works……..ish: get skin cream and rub it on you after you get bit, it should help a littli and try to control your itching, the more you itch the more the bite gets bigger and itchier. the only thing we can hope for is that in a few million years, the world will end and mosquitos will be gone (just be sure you have an spf of 1000000 for sunscreen,your gonna need it)
I am A+ and get bitten all of the time. I get quarter to half dollar sized whelps with each one. I have found that putting ice on the bite helps. It reduces the swelling and thus the itching. If you can keep from breaking the skin on the bite it will heal much faster.
AH! I have type O blood and I will be the ONLY person in a group that gets bitten! Everyone thinks I’m whiny because they don’t seem to be getting bites. Mosquitos and fleas have ruined the appearance of my legs forever. I hate the smell of deet. I wish there was another way! Thanks for the info.
If mosquitos are attracted to CO2 or people who exhale more CO2, and if “thinking” cause the brain to use up more 02 and give out more CO2, then “thinking” may be the key to mosquito bites?
this is alot lol (:
im heela bored ):
I never get bit, but i always have a good laugh at everyone else that does. I can be camping, at a bbq, ballgame, it doesn’t matter, I just don’t get bit. My wife gets eaten alive, even when she uses repellent. I don’t use repellent, cuz I DON’T GET BIT. For all you bite sufferers, let me just tell you how nice it is to never have to worry about mosquitos. sorry, but I just love to rub it in.
Ugh seriously, I am type O and every time I step outside my arms get all their blood sucked out! I don’t know anyone who gets worse bites than me. It’s funny though because I’m so good at ignoring it that it doesn’t even bother me, and if it does get the occasional agitation, it feels good scratching them!!
The funniest part of the whole article is the photo. The pictured insect is not a mosquito (Culicidae) but a crane fly (Tipulidae), and these do not bite at all.
I am an O Blood type, I drink beer and never try to kill them…so Im pretty well the prime candidate. I sat outside one night after work with a beer in 20 minute I got 26 bites on my back, the other two outside didnt get bitten at all.
I’m AB-, usually have a 97.2 body temperature. My 8 siblings have the same blood and temp. None of us ever got bitten by mosquitos, despite living in mosquito laden Michigan woodland area. Our parents are bitten at a normal rate. ALL of the 24 grandchildren of various blood types are bitten at a high rate, several requiring medical care after campouts, etc.
Until I went to nutritionist and my diet changed from almost exclusively meat, milk, and junk food to one containing whole grains, fruits, and vegetables. Since my diet change in 2006 I have been bitten several times each year, and this summer (2009) I was bitten 7 times, and the sites got itchy and red. That never happened before.
Hormones? Age? Inheretted immunity, then acquired intolerance?
I blame the vegetables.
I’m 13. I’m type AB and I had gotten bitten all over my arms and legs when i was smaller so much, that i went to the doctor once{around 10 or 11 years old} . it was itching horribly. my mother even went as far as repeatedly changing my bed sheets because this happened over night. She bought a spray and sprayed me with it. It was to repel against the mosquito. I still experience getting bitten a lot. It’s quite annoying.
I never get just one bite. Usually more that 5-7 and then they come back for more and bite up to 11 times. these are the “normal” times i get bitten. Like I stated above, I went as far as seeing a doctor because my arms and legs we full of bites. If I showed someone, they would freak out. I’m honestly fed up. I’m writing this now because I’m experiencing the itching on my legs and hands as I type this.
The picture given is not that of a mosquito! It’s a crane fly (Tipulidae)
I am a researcher working in an unrelated area; however,the above discussion seemed very interesting to me. I am just wondering if anyone has looked at the concentration of the specific protein types in the blood that mosquitoes are looking for and the number of bites. Thanks for the article and everyone’s comments.
thank you for a wonderful article. now my colleague and I are aware about mosquito bite in general
thank you for a wonderful article. now my colleague and I are aware about mosquito bite in general. that what an awesome information that could help my topic.
Interesting post, I’m an ‘O’ and I rarely ever get bit. Never thought about it much before though.
for years and years every time i go camping im the ONLY one who gets eaten by thos damn bugs .When i was 10 are atv got stuck 10k away from help and we had to walk all the way there . my back was covered in bits and the sad part is they had to bite thru jacket
I’m B+ 56-year-old female and hardly ever get bitten, although I used to when I was younger. I live in climate where mosquitoes are prevalent except in winter.
There seems to be very little pattern with blood type on the above posts….many of you do not note whether you are rhesus negative or not? Maybe this makes some difference too? I also think it is dependant on the type of mosquito…has to be! I rarely get bitten in Europe but on a recent trip to Egypt I got eaten alive – over 100 bites over two evenings (in clusters) and my four friends had around ten bites between them all!!! I am B- blood type. Wish they could eliminate the world of these little pests!