Something like drew's dirt mix basically. I think you should get a dirt box from drew if you can, drew is also currently out of stock too. Drew's stuff I think is some of the best formicaria for ants.
Edited by TechAnt, August 18 2020 - 12:30 PM.
My Ants:
(x1) Campontous semitstaceus ~20 workers, 1 Queen
(x1) Camponotus vicinus ~10 workers, 1 Queen (all black variety)
(x1) Tetramorium immigrans ~100 workers, 1 Queen
(x1) Myrmercocystus mexicanus -1 Queen
(x2) Mymercocystus mimcus -1 Queen
(x1) Mymercocystus testaceus ~45 workers, 1 Queen