My ants have probably outgrown the amount of ants Empires of the Undergrowth can display without crashing ;D
Using the pictures from the 24th I made a COUNT.
This is the nest. I gave every recognizable ant a blue dot, then divided the nest into small sectors and counted the ants in those sectors by giving them a purple dot.
These two outworld pictures were taking quickly after another so there shouldn't be too much fluctiation. The amount of ants in the water tube is an educated guess based on experience. In the end I counted 79 ants and rounded them up to 80 (as seen in the first picture).
This brings us to the final number of
Note that this count isn't their EXACT population - sometimes I had to make hard guesses when there were overlapping ants and obviously it does not include ants that were not visible, like ants hanging vertically on the backside of nest walls, ants in the connector between the two nests, ants in the water tube conenctor and the quite massive number of ants in the tubing from the nest to the outworld.
Those invisible ants included I would estimate them to about 750-800 ants in total.
And just as a reminder... they were 4 workers in March.
Satellite colonies are usually established in warmer places to increase brood development speed (mostly pupae) or near food sources. The queen usually stays in the primary nest, although brood may be carried into the satellite nests.
Some ants (like big colony Camponotus species) can be oligynous which means they have more than one queens with each having a seperate nest (they usually attack each other when they're in the same nest but it works as long as they're in different places, this is very hard to successfully pull off in captivity though).
The supercolony ant types can make new nests by splitting off a part of the colony that moves to the new site but that's not really a satellite nest anymore then.
In the picture with the two nests the queen is in the right nest in the upper left corner below that patch of pupae. You can recognize her by the big thorax segment where the wing muscles once where (the majors have much slimmer middle segments).
Can't find her in the other pictures, she probably moved into the outworld access tube (she doesn't like light and that includes the red camera focus light).
Interestingly this Camponotus species doesn't seem to be one of those ants where the workers constantly hang to the queen and tend, feed or groom her all day long. Most of the time she just sits or walks around in the nest and doesn't get bothered by her children.
The Solenopsis queen on the other hand is literally covered in workers most of the time.
I guess your queen is either Lasius flavus or Lasius umbratus/Lasius claviger, depending on the size of the head. She could also be Prenolepis imparis or a Nylanderia species, depending on your location. Those all look very similar.
If you post pics I may be able to identify her.