It's been about 7 weeks now in the new formicarium. They have completely excavated across the entire formicarium. There is still a little excavation going on, but not much anymore. They are just growing the colony. I don't know how many ants are in the colony now. I would guess anywhere from 300 - 500. I haven't been able to find the queen for several months now.
My Pogonomyrmex occidentalis colony was getting to large for their existing soil formicarium so I decided to build a larger one. Hopefully this one will suffice for awhile.