At the moment, my Tetramorium colony is living in a basic tubs-and-tubes setup in a medium sized kritter keeper. It's been working well enough, but lately I've noticed that the cotton balls in their test tubes have been shoved right to the end with little to no actual water visible (in the oldest they've actually dug into the cotton ball) and also that they've been really drinking up the sugar water in that test tube. I'm taking this to mean that they're in need of new housing; I've added an additional two test tubes for them to move into, but it's meant as a temporary measure to get them to hibernation. Once I take them out of hibernation, I'm planning on moving them into a different enclosure.
At the moment I'm considering a natural setup for them, consisting of mostly dirt with a drainage layer.
What kind of substrate would be best suited for such a setup? Given where I've seen wild colonies nest and after doing some research of my own, I'm under the impression that Tetramorium would do well in a more arid setup, with some kind of sandy soil (maybe sand + coco peat mixture), but I'm not sure if that's actually ideal for them or not, or if I'm overthinking things and Tetramorium are adaptable enough to adjust to any kind of soil.
Or would Tetramorium be better suited to a separate formicarium + outworld setup? That'd be a bit more awkward for me to set up as I have no experience in building formicariums (nor the funds to buy a premade one), but it doesn't sound completely undoable even if it's not my preference.
