I bought this hibiscus tree in the fall and noticed that there were ants on the plant and in the soil. I brought the plant outside and sprayed it with Safers Trounce and it seemed to solve the problem for a couple of weeks but the ants keep coming back. Before the leaves flower there are black little bugs??? on them and I believe this is what is attracting the ants so I am spraying on this but for some reason I can't get rid of them and I need to solve this problem before the fall. I don't want ants in my house!! Is there something else I should be buying?