interesting, I'm 0 and a favoured mosquito target, and my wife is A and does not get bit very much.

We have two kids to which the same dichotomy applies: I now need to check what blood type they have!

Sounds like you already know!

I'm a type 0 magnet myself

Me, too, alas.

Me three. If there’s a single (female) mosquito in town, it unerringly zeros in on me.

I’ve read that mosquitoes are attracted to “high sugar” (i.e. higher amount of polysaccharides) blood types, which O is. The Chinese even have a saying of people who are mosquito magnets: “You have sweet blood!” (I was told this a lot when I lived in China.)

That said, mosquitoes also seem more attracted to fresh meat, i.e. new and different smelling prey. Live in one locale for a while, and predation by mosquitoes seems to diminish. Perhaps it’s an ancient defense mechanism.

From TFA:

Scientists have put forth some theories to explain why mosquitoes swarm to some of us more than others, including one idea that differences in blood type must be to blame. Evidence is weak for this link, however, Vosshall says.

can confirm, 0+ and unhappy recipient of their attention way above most people around me... it can get pretty dangerous in places with malaria, dengue, yellow fever etc.

I'm O+ and I never seem to get bit whereas my B- wife does.

Am O-. Wife gets bitten way more than me and is not O.

I'm B+ and wife is O+, and I'm always the one bitten most

I'm O-positive, and I tend to barely ever get bitten by mosquitos when I'm in a group (but if I'm outside alone sometimes I'll get a bite or two). The only theory that I've ever had was that I sweat an exceptional amount when even feeling slightly warm, and given that mosquitos tend to be out in warmer weather, I've wondered if my odor discourages them if better smelling targets are available