Ponera Pennsylvanica is a species I also want to keep. I like all ponerine ants because of their unique body shape, and especially P. pennsylvanica for the fact that it's semi-claustral (or so i've heard. can someone verify?)
Um... pretty much all ponerinae are semi claustral. P. pennsylvanica is probably the least interesting ponerinae out there.
I mean, I'd rather keep them than most of the Hypoponera species here (except for H. inexorata). They're actually bigger and more elongated than Hypoponera species. Luckily for me, South Carolina has a few more Ponerine species. Cryptopone gilva and likely Odontomachus brunneus both live in SC (Odontomachus brunneus hasn't actually been found in SC, but has been found a few miles south of the border). We also have Gnamptogenys triangularis which isn't actually a Ponerine, rather an Ectatommine, but was once classified as a Ponerine.