some ants farm the aphids, so if you get rid of the aphids, you get rid of why the ants want to be there..
how are the ants getting into the gb's? you can put a little petroleum jelly on the gb legs (or put the legs in a bucket with water)
I did the petroleum jelly, worked pretty good, except for the ones who seem to have nested in the top of the gravel. Or have climbed up anywhere a branch, leaf or vine touches. I know ants are useful, but they really need to be useful elsewhere, like my neighbors yard biting them.
People cry because they are sad. For example, I cry because other people are stupid, and that makes me sad.
I use dish soap. Just get it on everywhere they would climb (similar to the jelly) except what it seems to do is prevent them from leaving their pheromones. I put about a 2 inch barrier around and area in the sand and they leave a trail AROUND the area that has the soap (and I can't SEE the soap anymore, it sunk into the sand). I'm sure at some point you may need to re-apply, but this home remedy seems to work. I have no clue how or why, and it may not work for you, but it seems to have done the trick.
This is a 2 pronged effort. On the other front I am destroying every ant mound I can find. I normally love to keep critters in my yard, but I have been bit thousands of times too many. It's nuclear warfare time. I use the water hose to annihilate their ant mound and I keep applying this organic ant poison (green light I think... just ran out a few days ago).