It took the ants only about 5 hours to begin their tunneling. They started using one of the holes I had provided, and it looks like they were putting little gel clumps all over the top, wherever they pleased. At any given time, it appeared that only about 3 ants were working on the tunnel; the others were still interested in climbing the walls or milling around.
After a good night’s sleep (for me at least), I woke up to find the tunnel had grown slightly. The ants had made contact with the habitat wall and seemed to be working upwards. The gel clumps were being placed along the edges of the habitat. I have no idea how they got them up the sides of the wall…
About 24 hours after the ants had been placed in the habitat, they had widened the tunnel, and reached the surface, creating another entrance. There are a lot more gel clumps! It also looks like they have begun a second tunnel, also using one of the holes I had provided. More ants seem to be working, though many are still climbing around and ‘resting’.