Here on the west coast, I use Terro for ants both indoors and outdoors. they offer separate types for each. Very effective. It is Boric acid in liquid form. When the ants started coming in my kitchen window and depositing aphids on my Sweet Basil, it was war! Just the thought of scale on my orchids terrirfies me! So hard to get rid of. I sure didn't know that ants brought it to you.
Here's the "nice" thing about boric acid, it does in roaches and ants, but has a table salt response in higher animals...in other words, don't eat a lot of it, b/c it can be bad...but it is toxic to insects...can desicate them when in powder form, and toxic to their digestive systems, if taken in. Everything has a deadly aspect to it, even water, but boric acid tends to be easier on the rest of us than some of the organic pesticides available.