I just picked up a bunch of new balls (100-150g), which are in 6qt containers. But I have observed that a lot of them, especially the smaller ones, are sitting on or in their water bowl which is at front of tub. By a lot, I mean at some points when I have looked, 4/9 were doing something like this. (other times less)

From reading forums I understand possibilities:
* Soaking for shed -- but seems like too many of them at once
* Killing mites -- I have seen none
* Cooling off -- Until tomorrow I don't have heat tape in this rack so keeping entire room and temps in their tubs in low 80's (80-84). Even at 80 I see them doing this, so I don't think they are trying to cool off? Other context: I believe that several days before I got them, they were without heat in a cool house, hopefully not much less than 70. So relative to that does 80 now feel hot?
* I also put newspaper in which they are not used to, maybe they don't like the feel

They all look really healthy to me, and I also got most of them to eat F/T rats last night, so I take this as a good sign of their health too (and they are used to live).

Did I miss any possible explanations? Currently my best guess is temperatures.