Yes the ants milk the aphids but it is the aphids to need to get rid of not the ants!

My hollyhocks' buds are covered with "sticky" ants, but no sign of aphids. So should I just keep an eye out for them in the meantime? Last growing season, the hollyhock leaves had black spots on them--i think they had a disease, not infestation of insects. I'll leave the ants alone. Thank you for your fast response!