Hello bmb1bee;
I really like what you've created with the fossils in the nest and outworld and how it makes watching the ants so much more interesting. I hope you don't mind if I show you an outworld I made a couple of years ago.
This outworld was made for a large Camponotus colony, I went all out and raided my fossil and shiny stone collection, along with plastic plants and parts of an old ant nest, I tried to create an outworld that would be interesting for the ants and for me. I imbedded the fossils in the grout/vermiculite mixture that forms the base of this outworld. The large fossil in the center made a convenient feeding platform.
The skulls were a bonus, and the ants seem to like them as they often hid inside. They'd drag food in there where they broke it apart and then took it into the nest. They used the pieces of old ant nest like guard houses because I placed them at the entrances to the outworld from the nest and at the entrance to their sugar/water feeder.
This outworld is divided into two sections, I let them into the right, smaller side early in the season and then the larger side as well, later in the season as the colony size increased. I was very interested to see how they took advantage of the opportunities to take command of the outworld with its many hiding places and places to use like command posts.
I hope you get some ideas from this example. I think complex outworlds give ants a more realistic natural experience and this gives them an opportunity to demonstrate more natural behaviours as they go about their activities. They're certainly more interesting and entertaining for me to watch!
RPT
My father always said I had ants in my pants.