I moved them on the weekend into a multi-level cage and decided to watch. The neuro girl (whom I'm fairly certain we'll be keeping so we better start thinking of a name), stayed on the bottom level .... for a day. When I saw her on the second level, my heart lurched, but there are cozygloo's and things under the ramps/shelves and she just sort of veered onto them and down to the bottom level and so far seems to be managing fine. I did notice she can't go up and down consistently yet, so I have rigged up a water bottle to go on the inside of the cage at the bottom level so she can reach it. (heavy water bowl kept getting knocked over).
So far everyone is doing very well. They are mostly on solids now and so far, no signs of MC. Weaning next week and then many will go to their new homes. Out of 20 babies, two had died, one early on and one later b/c of MC, out of the 18 left, 14 are tentatively adopted. (I have a woman from NY that wants 2 of them but for the life of me, I don't have a clue how I'd get them to her. She seemed to think a rat train could be made).