Glad you liked my article @benfink. In response to your question about how long do I expect these populations to last, there are several things to consider, but some of the original ants should live at least three full months.
Uncle Milton, who was the pioneer and king of the Ant Farm®, did not ship queens with his farms. You probably found out what I found out, it is against the law to ship a queen ant. Uncle Milton does give a guide for the ants he ships and in the guide it says to expect the ants to live, and I quote, "they should live one to three months." For one thing, we do not know how old the ants are already when we capture them.
Now I set up my first kingdom in late June last summer and kept track of the days they lived. The final ants lived for 97 days. In the other two kingdoms I kept replenishing the ants by going back to the colony from whence they came and captured some more, and those kingdoms lasted longer for sure. I released the remaining ants back to their colony in late October as winter was approaching here on the East Coast. It was fun observing some of those family reunions. I captured footage when I reunited some in my kingdoms.
I did an internet search: What is the life expectancy of ants? and it seems the general consensus is that they live one to three months. The queens live for years, thirty I have heard, and they keep replenishing the worker ants so the colony lives on. Deborah Gordon, an entomologist at Stanford University, has followed the same colony for years, if I remember right it's been 28 years. She has some interesting videos on the internet.
I plan to set up the ant kingdoms earlier this year and I will continue to replenish the ants. Last year I had them June to October, and it was just the last four days of June, so almost July. This year I am looking May to October, and I will release those still alive back to their colony.
Now, if it your hope to have a queen to keep breeding ants, do an internet search: how to catch a queen ant. You will see youtube videos and a how to step-by-step on wikihow.
The last item to consider is what species of ants. I am most familiar with black pavement ants. Uncle Milton ships harvester ants. I don't know if the species of ants matters in the life expectancy.
I hope this answers your question.
many thanks for the detailed answer @michaelbkearney! fascinating stuff. Looking forward to following your ant adventures