Do mosquitos see CO₂

I was sitting in the car last night waiting for some friends to arrive for a bicycle ride.  As I sat there, the Minnesota State Bird population was quite thick buzzing around the closed window.  I think that I read somewhere that mosquitos are attracted to Carbon Dioxide.  But, I wonder if they are attracted to the smell, or can they actually see it?  Sounds like a good research project for the Department of Agriculture to pursue.