Moving Babies

Question
I am breeding mice for snake food because my snake has to eat too and I am over an hour away from any place that I can buy live food from because the person I got him from only fed him live so I still need some live to get him over to frozen. But my main quesiton is why doe one doe constanly move both litters of babies to one house and the other one moves them back? I was watching them for about 10 mins yesterday one doe would come out of their blue house with a baby and leave them in their brown house and then return to blue one again, and the other doe would just follow her and pick up the baby from the brown house and leave them in blue one. I think that they probably gave birth at or around the same time because I housed them together for a month with no issues introduced the male, who is on his own right now, with no issues. Just wondering if this is something normal with mice or maybe just a personality quirk of mine.

Thx,
Randy

Answer
I can't say this it is normal or abnormal, only that I have had many different animals (mice, gerbils, degus, rats) do the same thing.  I know for sure that with rats and degus communal raising is common, but cannot promise that way for all rodents.  

Good luck!