I've been on the lookout for crazy ants, but haven't seen any. Just a matter of time. They sound worse than fire ants, which don't usually have an interest in coming inside a house. There's several other kinds that get in my pots, just regular "piss ants" and a couple smaller kinds, red and black, sometimes orange.
I believe the nesting activity in pots kills some of the roots, which the ants eat. The nesting activity also alters the drainage as they build their nests to be as waterproof as possible. They also farm pests on the plants, which can kill them, and introduce fungus and other pathogens. The ants bring the aphids to gather nectar from them. Then the ants eat the dead plant material, and the dead aphids if they don't have another host plant for them. They may not eat live plants, but they do kill them. Not that they are organized to do it consciously, but their regular activities can be deadly to plants. Entire farm crops can be decimated this way. IMO, they are not at all benign around plants, but quite the vector of pests and problems. The most promising research/documentaries I've seen are turning the ants into zombies that don't work, so the colony collapses from disorganization/starvation.
Watering with boric acid will change the PH in the soil.
