yep. massive amounts of sweat. i watched them land and take off like they were grossed out. whatever. i was halfway through my run when i stopped and they were making test landings on me.
I submit for your consideration the hypothesis that it wasn't the sweat, per se, so much as what it carried in your particular case that fended them off. No offense, man.
When I stopped for a water break at 5 miles on Sat. morning, a cloud of nasty biters surrounded the group of us and we all were attacked. They landed and fed and were smacked with great enthusiasm.