Mission success! Very happy to have found these and not underwhelmed in the slightest. Such cool ants.

One colony was seen nesting near the base of a somewhat small (compared to other large trees in the area at least) Parkinsonia microphylla. The nest entrance was made in a small pucker in the wood, in the live part. There was exposed dead wood on the other side of the branch, so they likely nested in that part, but made the nest entrance in the other side.

The tree trunk split into three directions, they nested in one of these branches.

Only a few workers were seen out at a time and they were very timid. Workers would rarely exit the nest if I was around. To my surprise, one major (is the correct term for this genus soldier?) was seen out of the nest near the nest entrance. It fell off the tree and played dead when I tried to get a photo of it.

I was able to get some workers to stay still with some honey.

I suspect that Forelius are likely this species main competitor for food and resources as many were seen going up and down the Palo Verde's in the area.