ant dude - I appreciate your concern
, unfortunatly it's quite difficult to find other ant spp. in my area. The S. invicta are virtually ubiquitous and are likely responsible for the lack of other ant spp.. I'm hoping to find a Florida harvester ant queen in the summer; that would be my top pick of native ant species.
mpir - I think I have a reasonable understanding of their prefered habit from observation, as you said. I know there are a few other yanks that use these forums, so I was hoping I could find someone who has kept S. invicta and could help clarify the ideal conditions for captivity.
Also, I'm going to take several measures to keep the colony contained. Fortunatly, they are very bad at climbing smooth surfaces compared to many other ant species, which will be really helpful in containing them. But, just in case of an escape, I'm going to be keeping this colony outside in a screened in porch when they start to develop into a larger colony.