I've had my colony of 500+ Polyrhachis dives for just over a week. Started them off in a single basin where they worked on building a new nest. On tuesday I added a smaller 30x20x20 basin for food, water, and a trash area. Since then the colony has moved to the tube between the basins. I'm fairly shure given time the'll move back to the nesting basin. But wonder why they would leave a dark nest for a tube thats exposed to more light.
Its a common problem, i described it some months ago. They use the tubing as a nest thus blocking the passage between the two basins. even if they decide to move back the tube would still be sealed with their silk and all the trash they use to build a nest. In my opinion tubes are not suitable for this species. You could try to get them out by covering the tube with some wet towel and keeping it wet all the time will cool the tube down...
My Polyrhachis dives did the same thing. I sealed the ends of the tubing and changed it for a fresh one, then put the tubing with the nest in it off the floor of the basin, just put on two pieces of wood. They fixed the entrances in a few hours and seem to be very happy with the solution.
I think clear tubing is a great nest as you can see a lot of what they do inside.
i curious what type of tubing was it, show us a picture
i have just got mine and they do not seem to mind at all with the tubeing