Let's see, to get in the grow bags on the deck, they would have to crawl up the side of the grow bag and down inside some to get to the potting soil mix. I have a spray bottle I bought a short while ago of “Elementals” household insect killer which is an Ortho product and the active ingredient is 100% natural soybean oil. Never had that before but I saw it when buying household kitchen cleaner and that sounded good since it would be okay around my Yorkie - says it's safe around pets and children. It kills ants among other household insects. I would spray the ants in the grow bags with this stuff if they got in a grow bag.
I have bags of Miracle Grow Potting Soil Mix on my lower deck under the roof and they have zipper closures on them so no bag is open for ants to get into.
So, maybe you should get this “Elementals Home Insect Killer” and spray those suckers. I think I got that at Kroger but it could have been Walmart since I've had to go there to pick up Walmart.com items recently.
Ants and snails..I hate them. I planted a ring of flowers in the backyard about a week ago..angelonia, profusion zinnias, and then threw out some alyssum seeds.
I ringed the ring with deadline snail bait, and the ground under the plants with Sevin.
This morning I found 13 snails under the zinnias..I think they parachuted in to avoid the ring of death.