Why Are Mosquitoes Attracted To You?!

Why Are Mosquitoes Attracted To You?!

Are you the person in the group who’s always getting bitten by mosquitoes? Because I certainly am and science has shown that this is a thing – that mosquitoes are more attracted to some people than others. And the reason for that is at least partially genetic, which is why this video is supported by 23andMe, a company that reads sections of your genetic code and then helps you understand, what’s in there. Now, they’ve actually been involved in some research that has identified particular spots on your DNA that make you more or less likely to be attractive to mosquitoes, and in this video I want to put that to the test. So I flew to New Mexico State University to meet mosquito man Professor Immo Hansen. Everyone: Hello! Hansen: We have a collection of lab strains Derek: Here, he maintains colonies of many different species of mosquitoes, and one exotic strain he actually feeds with his own blood(!) Hansen: No, no, I’m serious. These ones are made from my blood. D: Really!?
H: Yes! Absolutely, yeah. D: You feed these!?
H: And I’m the only one feeding them – I can’t ask my students, you know, that would be a nightmare H: getting permissions to this room here.
D: How do you blood feed them? D: With just, sticking your arm in there?
H: Well, I just put my arm in there and wait D: Is it psychologically itchy or…?
H: No it is really itchy [laughs] H: Yeah, and I’m getting, I mean, 25 bites or so right now D: Mosquitoes need our blood proteins to make their eggs, so only the female mosquitoes bite. The eggs hatch into these wriggly larvae, which develop into pupae before becoming flying, adult mosquitoes. Then they, once again, seek out vertebrate blood to make more eggs. The whole lifecycle takes just two weeks! But what I wanted to know is: am I a desirable target? D: How can we figure out if I’m attractive to mosquitoes? H: Okay, we have a Y-tube, basically, which has a holding chamber. We put the mosquitoes down here, H: there’s a little fan inducing a draft, something like 4 m/s. We’re gonna insert a bait into one of these chambers, in the green or the yellow one. D: So, by bait, you’re saying me?
H: Yes, you, exactly.
D: [laughs] H: You put your hand in there. [It] would be good if you would rub your hand first, so H: If you’re sweaty…
D: Get some oils?
H: Yes! D: This is the right spot…
H: That’s where the good stuff is, exactly. H: Almost feeds exclusively on humans. They are really specialized on biting humans. D: That’s good to know…
H: Yeah
[both laugh] H: There’s 20 mosquitoes in the holding chamber. D: And they’re gonna decide whether to come and find me, or go down the other side and… they find nothing. H: Right.
D: We’re releasing the mosquitoes. I see them coming! D: Oh, he’s chosen wrong! H: Do you see that? H: Man, you are attractive! D: Really?
H: I mean, sorry I-
[both laugh] H: You are a strong attractant to mosquitoes. They all went in your direction.
D: None of them went the other way! D: (laughing) This is amazing! H: Well, there’s one stranded in here
D: I did not expect to have such a strong… response, like D: You see all those mosquitoes… D: This type of test was actually used to discover that the basis for our attractiveness to mosquitoes is at least partially genetic. Researchers recruited 18 pairs of identical female twins and 19 pairs of non identical, or fraternal female twins. Then they used the Y-tube Test to evaluate the mosquito attractiveness of each individual, measured by the fraction of mosquitoes who correctly flew to the arm of the tube where the twin was standing. What scientists found is that the mosquito attractiveness of twins is correlated, that is, the more attractive you are to mosquitoes, the more likely your twin is, too. But that’s… not all that surprising, and could be caused by environmental factors, or a common diet. But, comparing identical twins to fraternal twins revealed the correlation was higher for identical twins. This strongly suggests genetics influence how attractive you are to mosquitoes. Since the identical twins share more of the same genes than fraternal twins, this explains why their mosquito attractiveness would be more closely correlated if it really is genetics that determines how much mosquitoes like you. D: With that last test, I was clearly attractive to these mosquitoes.
H: Yes.
D: Except we weren’t comparing me to any other human, D: we were just comparing me to a control, no human.
H: Exactly, yes. D: So, what if we compare myself with my wife Raquel? [laughs]
H: Uh-huh? D: Normally, I get bitten and she doesn’t.
H: Okay.
D: So this should be a good test… maybe? D: To see whether under lab conditions… H: We can we reproduce your…
D: We’ll reproduce our anecdotal finding. That I’m more attractive.
H: Exactly, anecdotal evidence a little once again H: They are a little…
D: Once again… D: …preparing. H: Okay!
D: Hands in position!
Raquel: Yeah. H: Yeah, see, they actually start to wake up. They… smelled something. Something’s going on here.
R: Here we go. H: Okay.
D: What are we seein’? D: Whoa! D: I’m getting a good amount over here, but so are you? D: Let’s see. I think I’m getting more. It looks to me like you got three. H: Okay, I’m gonna stop the experiment right now.
D: Alright. H: *chuck!* Okay, now let’s count. I think it’s seven on your side here? Lab assistant: Five in the holding.
H: Five in the holding. H: And quite a few on your side!
[Hansen and Derek laugh] H: So, who gets bitten?
D: I get bitten.
H: You get bitten! H: In reality, we would repeat this experiment, maybe eight times or so. D: Right.
H: And switching you guys around, but I think this is a good way to show how this works. D: Okay, so that result was not particularly scientifically rigorous, but it did reproduce our experience in the wild, D: which is that I am much more attractive. ….Well at least when it comes to mosquitoes, than Raquel. D: But the question is, I guess, does this come down to our genetics? R: Yeah, so, we spat into some tubes and sent them off to be tested.
D: Right, and we were interested in seven particular D: locations on our DNA, which were located in a 2017 study that involved 23andMe. D: So the way 23andMe works is, when you sign up, you can opt in to be part of research, D: and 16 000 people agreed to be part of this study and rate their perceived attractiveness to mosquitoes. D: So then what the scientists did was a genome-wide association study, that is, they looked at all the DNA D: of all of those participants and tried to see if there were commonalities amongst the people who D: said they were attractive to mosquitoes and that were different to the people who said they weren’t attractive to mosquitoes. D: And they identified seven particular locations on the DNA. Seven single letter changes which seemed D: to be associated with different levels of attractiveness to mosquitoes. D: So we have our results back, and do you wanna see them?
R: I do. I do, I’m very curious. D: Alright, let’s pull it up here. D: Okay, so of the seven locations that are related to mosquito attractiveness, it turns out we have the identical DNA at four of them. D: So you can rule those out.
R: Okay.
D: Which leaves only three areas where we actually have differing D: DNA. So, at the first location, you have one copy of a letter change which actually makes you significantly D: *protected* from mosquitoes.
R: Oh, no way! D: Yeah, it’s associated with decreased attractive to mosquitoes
R: Oh, that’s cool! D: I do not have any letter changes at that location. Now, at the second location where we differ, I have D: a letter change compared to you that makes *me* less attractive to mosquitoes, so more protected. R: Interesting.
D: If you look at the significance of those two letter changes, D: yours is about twice as significant than mine.
R: Okay. D: But still we both have a protective letter switch. So, in the last snip we actually differ significantly. D: And I have two copies of a variant that makes me more attractive to mosquitoes. D: This was the only snip which was associated with being more attractive to mosquitoes, D: and I have two copies of that change, and you have no copies of that change. R: So that makes sense.
D: So overall, I would say our genetics really adds up here. D: And of course, we can’t say that this proves that it is right, but it is definitely consistent D: with these snips actually being associated with your attractiveness to mosquitoes, and that’s sort of… D: borne out by our experience.
R: That’s so cool! D: Now, it’s unclear exactly how these genetic changes might make us more or less attractive to mosquitoes, but it’s likely that it has something to do with the odor or the volatile chemicals that our bodies give off, and due to the microbiome, the bacteria on our skin. One of the main signals that mosquitoes like to follow is carbon dioxide. So that means if you have a higher metabolism, or if you’ve just been exercising, or if you’re a bigger person, or even if you’re pregnant, you are more likely to attract mosquitoes. But mosquitoes are also attracted to some other volatiles that we give off, things like lactic acid, acetone and ammonia. But scientists have also found some chemicals that repel, or appear to impair mosquitoes’ ability to find us. Those chemicals we naturally give off are octanal, nonanal, decanal, and 6-methyl-5-hepten-2-one. So, why is this important? Well the researchers estimate that our attractiveness to mosquitoes is about as hereditary as height or IQ, that is to say genetics play a significant role here, so understanding that relationship is really important, especially when you consider that, of all the animals, mosquitoes have the greatest impact on human health. D: Are mosquitoes the worst animal of all time for humans?
H: Absolutely. H: Absolutely, there’s no question about that. Malaria has killed more people than people have killed people. They are the most dangerous animal in the world. D: By some estimates, mosquitoes have killed more than half of the humans who have ever lived. Now, that estimate has been debated and is likely too high, but even so, this year, over a million people will die of mosquito-borne illnesses. So if not half, certainly a significant number of humans have died due to mosquitoes, probably more than any other single cause, which led me to wonder: D: Do you think humans may have evolved this trait to smell worse to mosquitoes as an adaptation to avoid the diseases? Or… D: is it just by accident that some people are less attractive to mosquitoes than others? H: ……. H: …That is a really good question!
[both laugh] D: And while we’re on the subject of evolution, consider this: if you ever contract malaria, it actually changes your body chemistry to make you produce an odor that makes you more attractive to mosquitoes. Think about that! The malaria parasite has evolved so that, when it’s in its host, it makes the host more attractive to mosquitoes… mosquitoes are the thing that transmit malaria! It’s phenomenal! I mean evolution is incredible! [Veritasium logo] This episode of veritasium is supported by 23andMe, a company whose name comes from the fact that humans have 23 pairs of chromosomes, and the point of the company is to help people understand what’s written in your chromosomes. Now, at the minute, you can’t get access to the mosquito attractiveness test, but maybe, one day in the future, you will be able to. Right now, you can access tons of information about your physical traits, about aspects of your health, and about where you DNA and, I guess, you come from. So I thought I would share my results with you. I come from all over the world as you can see from the map, but significantly more from Europe, about 95% European. You can drill down into that and see that I’m largely British and Irish, and French and German, with a bit of Scandinavian. What’s interesting to me is, there’s a 3.3% South Asian which is something I think my family suspected, but didn’t know for sure, so it’s interesting the types of information you can find out which is stored in your DNA. So, if you wanna find out about the information in your DNA, you can go to So I want to thank 23andMe for supporting Veritasium, and I want to thank you for watching.

Comments (100)

  1. I don't think this guy understands natural selection aka Evolution

  2. I just killed two mosquitos now my hand is full of blood

  3. I'm very attractive to mosquitoes! I walk my dog and I get all the mosquitoes, no kidding!

  4. My brother had his DNA analysed at 23 and me, and it said that he was only 1% English, but, his parents, grand parents all generations that we know of were English. I actually can't understand how they could get it so wrong.

  5. so in short mosquitos are attracted to the most attractive person and its all in your genes therefore im hot af

  6. mosquitoes are also attracted to me, but i hate them and i enjoy killing them and i also enjoy pour bleach into water ponds.

  7. Disgustingly effective little hell spawns

  8. I can't watch this video it makes me motion sick.

  9. My mother and grandmother said it was sugar. The more you had, the more you got bit. …yeah, I know….

  10. 00:18 voice crack? Lololol

  11. How is that happening? I'd heard of microbes and other things affecting the behaviors of the host but this is wierd.

  12. Mosquitoes bites enjoy getting Milaria we need to kill Mosquitoes

  13. I think mosquitos are super icky like my step-dad

  14. Maybe your wife is secretly a mosquitoe, that's why she likes you. 🙂

  15. People that eat sugar also attract mosquitos.

  16. You must be part cow. Mosquitos love cows

  17. Yeah yeah, now show me the rest of your DNA :>

  18. Mosquitos are horny hentai vampires that shapeshifts and tries to rape you secretly

  19. I'm sorry if that comment is not scientific but good grief your wife is gorgeous! That being said … well I have nothing else to say besides good job. 🙂

  20. I was always told it was because i ate sugar a hour earlier

  21. REEE i hate mosquitoes they always bite me

  22. I'm not a fan of this video,it was fun which was cool.But it felt like trying to use a blunt object to perform surgery.Even the tube tests weren't controlled…I would like to see measured amounts of oils and oil makeups posted and a record of the diets associated with the oils.The video felt like an add for 23andme(It was sponsored by them)… peole who "Said" they were attracted to mosquitoes…mosquito breeds,vicinity to other pray,wind direction,proximity to habitat,body temperature,there's to many uncontrolled variables to call this a legit experiment….even in the video he rubbed his neck for the first run in the tube and then again for the second,she did it once,did she have powder on her hands or hair spray?Were they attracted to him because he had twice the amount of oil on his skin?Was he nervous?What…….Too many questions need to be answered from this video,from what we saw, all the way back up to who they pulled the data from and how the data was collected…Question Everything

  23. How many bloodsuckers, now, Haas Has Home?

  24. 9:49 I can't believe the underlying stupidity of that statement -.-
    Some Plasmodium protozoae are responsible for that. The Mosquitos are just their vector of transmission.

  25. Evolution!?! Really? Your funny!!!

  26. Are you breeding dengue mosquitos? Please find an a way how to trap this mosquitos.

  27. Me: opens the door
    All mosquitoes in a 100km radius: 😉

  28. What ill do

    Me: sees a mosquito

    *Calls the scp *


  29. I was just wondering if either of the 2 people tested had rh.negative blood.?

  30. Another thing to add to my list of: why high metabolisms aren't always good

  31. This man literally makes me feel dumb

  32. No thanks on the dna test. They have already been misused.

  33. Meaningless study. Mosquitoes are attracted to CO2 from your breath. They have eyes…they see you as a blood source, zoom in and bite accordingly for the blood meal

  34. Mozzies bite me to buggery. So do the fleas on my cat. It seems I'm just too tasty.

  35. I used to get bitten all the time as a youngster and later years. But now as an older adult taking B vitamins I don't get bitten. The insects do not like the smell of vitamin B.

  36. Mosquitoes are paid😏

  37. "Attractive to mosquitoes"

  38. Irony is mosquitoes does its business and kill people… she herself doesn't know that she is killing people this much… whereas other animals do realise the harm done in some way or other.

  39. If you do not want be trouble by mosquitoes, go for this Aspectek Bug Zapper, Both 20W and 40W. Good price and Brilliant Quality. On promotion now. Worth to own it!!! Click here:

  40. Heavy breather….end of story.

  41. She's more attractive to men too.

  42. me: open door for 00.00000000000000000000001 sec
    mosquitos: Allow us to introduce ourselves

  43. Basically, They need blood for babies

  44. In Haiti, they say they prefer people who eat bananas.

    I haven't had a banana or mosquito bite in 11 years.

  45. Mosquitoes bite me in my knee

  46. AAH it's so unconfortable to watch this video with headphones

  47. What a senseless test.

    Wouldn't it have made sense to add another potential host, for purposes of comparison? They had two choices, with only one potential food source. Why would they choose the end with nothing there?

    That isn't amazing.

  48. Tea tree oil. Lavender oil. Lemon works!

  49. I get terrorized by them

  50. Mosquitoes are not just attracted towards me, they even come to sing near my ear. They just love me.

  51. Because I have a thic b ass

  52. There's like 9999 people with me and the mosquitoes only bite me lol

  53. A mosquito is biting me right now as I watch this

  54. Only a little tiny part of it is genetic. Heat / co2 /food you eat. 23and me are collecting your genetics and your a fool if you give it to them

  55. In childhood mosquitos used to enjoy my blood but after teenage years they started detesting my blood. Don't know why?? May be they thinks my blood poisonous


    Everyone else: Stop trying to attract attention t9 yourself, there are no mosquitos, you are the only one that is beinb bitten.

  57. What kind of crazy mother f*{^#r feeds mosquitos with his own blood. They all deserve to die!!!

  58. It is actually coz of ur sweat smell

  59. They don't like cinnamon. Cinnamaldehyde is toxic to larvae.

  60. Why Are Mosquitoes Attracted To You?!,,,,BECAUSE THEY'RE BLOOD SUCKERS!!!

  61. Want to know why mosquitoes kill so many people???

    because they were infected with diseases to kill people..

  62. Remember when we leave Earth we are not fkn taking mosquitos with us lol

  63. I wish girls were attractive to me like mosquitoes

  64. I get bitten so much

  65. I am almost 40 and a South Carolina lowcountry native. This has been a lifelong problem. It is bad here.

  66. Wildcard monkey wrench variable worth studying: I’ve always had a gut feeling a key factor in an individual’s perception of his/her attractiveness to mosquitoes might be significantly influenced by the characteristics of their individual physiological reactions to mosquito bites. Ive observed in my own social/familial circles a class of folks who experience frequent sensations of being bitten by mosquitoes, and/or prolonged intense itching, and even uncommonly intense swelling, who coincidentally perceive a high personal level of attractiveness to mosquitoes…while at the same time observing peoples in same party equally beset by, slapping, & smashing swarming mosquitoes (and thus likely feeding the mosquitoes in similar amounts) who experience relatively minimal sensation of being bitten/minimal itching/barely noticeable swelling. They tend to classify themselves as less attractive to mosquitoes, when empirical observation seems to point to the conclusion they are equally as attractive. Takeaway: The physiology of the reaction to the bight may significantly influence the perception of one’s attractiveness to mosquitoes, even though the level of attraction from the mosquitos’ perspectives may potentially not vary at all.

  67. 500 spiders vs 30000 mosquitoes

  68. O god, that mosquito noise when you're wearing earphones !!!

  69. thats why everyone saying when they wakeup in the morning and say..i cant properly sleep tonight bcoz of mosquitos.and i like wtf … i am think even mosquitos dont like me..

  70. 1:30 thanks I hate it

  71. I've got news for ya guy, Raquel is far more attractive than you. Those mosquitos must be defective, lol. But since you both attracted some, attraction remains subjective. ☺ Thumbs up.

  72. Evolution is BS. Theres no proof that malaria "evolved". Macro evolution is mathmatically impossible! Micro evolution is nothing more than adaptation from preexisting genetics. A shuffling of them. You should research the flaws in evolution before believing this lie that lts a fact. Its not. Every form of evolution has been disproved. They have either been altered or flat out lied about. The truth of this is out there. You just have to acknowledge it.

  73. Mosquitos do not kill, it's only the vecteur of the killers that are Malaria, Dengue, Nil fever etc..
    Maybe we should just heal mosquitos from their parasites .

  74. i noticed that it depends on my diet wether i get bitten or not.

  75. So now I am not attractive to humans nor am I attractive for mosquitoes
    *Cries in a corner

  76. Mosquitoes ?
    I think cockroaches are worse

  77. Its nice to meet u name is mark mesquitto

  78. I learnt 8:40 from Narancia

  79. U r amazing sir……

  80. Accidently knocks over mosquito chambers

    Me: Light speed

  81. Imoo's death squad looks like mini versions of the bugs from Starship Troopers, the Arachnids.

  82. These Mosquito think I'm Bae 😔

  83. Yeah I'm
    They made my life as hell at night time
    God Help me

  84. So i am not sexy?

  85. the professor better be paying his woman handsomely well to have her put up with this type of nonsense.

  86. Me: reads title
    My first thought: coz my blood's hot, babe!

  87. phuck you. why would you make more mosquitoes!!! we should be getting rid of ALL OF THEM

  88. he is saving lots of lives by donating his blood

  89. hit like if u see the man backside

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