Mosquitoes are attracted to five things:

Carbon dioxide – mosquitoes are attracted to the carbon dioxide we exhale, both the scent and the amount.

Body odor – Bacterial colonies combined with sweat generate that sweet (if you’re a mosquito) human scent we call body odor. Without the bacteria, our sweat would be odorless; with the bacteria, our sweat is one of the more attractive scents for mosquitoes, particularly the malaria-carrying Anopheles gambiae, which prefers to bite humans.

• Secretions – About 80% of us are “secretors” or people who secrete compounds known as saccharides and antigens through their skin and indicate blood type. Mosquitoes are magnets for secretors. Once again, your classification as a secretor or non-secretor is determined by your biology and there isn’t anything you can do to put yourself in the non-secretor category.

• Blood type – Depending on the type of blood you have, you secrete different scents. Studies have shown that mosquitoes are most attracted to Type O blood and least attracted to Type A. No changing your blood type either.

• Lactic acid – Lactic acid is emitted through your skin when you are active or eating certain foods.

Studies have suggested blood type (particularly type O), pregnancy and beer drinking all make you marginally more attractive to mosquitoes.

Oh, @Lemley, I soooo get it. I have always been the most delicious person around.
Everything @zenvelo said, plus a couple of other caveats: eating a lot of non-citrus fruits increases your yumminess, and using sweet, fruity soaps and lotions does, too.
Using lavender products helps, it’s a natural repellant.
Good luck with this! I now make my own repellant, as I have found that the commercial ones don’t work any better, and 50 years of DDT and DEET are just too many.

I read somewhere that mosquitoes are attracted more to overweight people, since the heavier you are, the more carbon dioxide you exhale. Of course, we all know thin people who get bitten a lot, too, but maybe statistically the heavier people get bitten more.

Bcoz you’re an atheist..)

@zenvelo Wow are you google? Well I’m not a type O, I don’t stink much, don’t drink beer… not pregnant either :p But yeah, I must be seen as a buffet for mosquitoes. Lucky me!

@canidmajor Annoying, isn’t it? Also, how do you make your own repellant?

@jca I’m kinda small-ish Don’t want to imagine how it would be if I was bigger. More places to get bitten etc.

@imrainmaker And my blood’s going to turn them into vampires? :D

Just kidding…

I use essential oils. The initial cash outlay may seem slightly daunting, but a little goes a long way. I use a mixture of lavender, eucalyptus, citronella, and lemon oils, diluted with witch hazel, water, and a bit of vodka (so nothing will grow in it). You should be able to find recipes online, but I use about a half teaspoon each oil, 2 Tbs vodka, and the rest witch hazel and water in a 4 oz bottle. Shake thoroughly every time. I have found this to be pretty effective, but it sweats off fairly easily.
Good luck!

@canidmajor Thanks! I am a bit tempted to drink it :p

Well, I imagine that would be startling! :-)

I heard that eating bananas attracts mosquitos. Also swatting at them will make them worse. Be like a zen master and most of them will not bite you.

@RedDeerGuy1 Then they should bite monkeys. Do they?

@Lemley I don’t know about monkeys. I’ve never seen one in real life.

@ zenvelo thank you for the skeeter info. It was the wife that proved to me that mosquitos really do have preferences when it comes to people. I’m actually bite free as long as she’s in the same space as myself. They merely irritate me with their enthusuastic humming on their way past me to bite her. The blood type thing is something I’d never heard before. I’m A+, while she’s type O. Bon apetit!

Mosquitos like people with iron rich blood.

So anemics are ignored for folks with “magnetic” pesonalities?

I do remember reading that they can’t fly worth a damn, and even a slight breeze from a fan is a handy defense.

Well, I’m type A+ but they still come after me!

Also some people react badly to the bites. My husband gets a small red spot which isn’t itchy. I get a small red spot, surrounded by a hard white-ish lump, surrounded by a giant hot red swelling. And it’s massively itchy. I put hydrocortisone cream on mine.

@Stinley: I tend to itch mine until they bleed. When I was younger and used to be outside more, I’d have red spots all over my arms.

@jca you’ve got to be strong! No scratching!! Try stroking your skin if you feel an unbearable urge to scratch or after you have scratched and made the itch TEN TIMES worse. And apply the cream.

@Stinley I can totally relate! Mine get white, swell like crazy, and all nearby skin gets red.

@jca Eeew, don’t scratch them! You could get an infection that way.