Don't worry about it. Some seem to be more attractive to ants than others. I have one that I never cut to bring into the house for that reason. The ants love it. None of the rest of the bushes attract them. I think it must be a pollen secretion or something. It doesnt' seem to be harmed by them at all.

Ants are not only taking advantage of the nectar source, but are eating the pollen, as well. They may be taking both back to the nest.

That happens to my rose of sharon and I don't like it.
I would kill them off if they bother you. However, do it as organically as possible. If the flowers aren't being distorted, as my shrub was, I would leave them alone.

bumblbeez ants devour my rose of sharons.what do you use or can we do to control them?should we fertilize them in the winter too?