Mosquitoes

Will someone please explain to me the purpose of mosquitoes, other than wreaking havoc on innocent unsuspecting skin? The mosquitoes here are not as massive as the ones I remember from the delta, and they don't hurt nearly as bad when they bite, but man I cannot handle all of this itching! Turner has several bites, and they don't even seem to bother him. Go figure. As the facebook page says, I wish they sucked fat instead of blood.