Will B is spot on. If you can see them, they're not a problem.
Avoid spanish moss and palmetto bushes.
They are worse than yellow flies, no-see-ums, fleas, fire ants...
Mosquitoes aren't even remotely in the same league. I'd rather be stung by a yellow jacket than get into a mess of chiggers. First time it ever happened to me (I was just a kid--nineteen-, twenty-years-old, back in Louisiana when I was working land surveys out in the swamps) I had purple welts the size of quarters on both legs and itched to high heaven for almost a week.
Those were the days...