I saw this on youtube about putting an polystyrene 'wall' into a test tube with a founding gyne, helping the more agoraphobic ones to settle down and creating a tiny outworld.
But once a colony gets a bunch a workers, they'll probably want to get rid of the wall. I imagine strong or big ants like Messor or Camponotus have no problem demolishing polystyrene, but how about Lasius or even tiny Temnothorax ones?