i have been keeping my female rats ( two per bin) together when they have babies successfully but this last go around i had one of my more dominant females take all the babies while the other female gradually lost interest in taking care of hers.

The dominant rat basically raised 24 little babies by herself, there was a noticeable size difference between them and other litters i have had as well as a much more prolonged growth period. I am hoping this dosent happen again but i have a spare bin now just in case to separate the mothers.

A major problem with this happening is that the dominant rat lost a lot of weight because of the stress and demand put on her body by all the little guys so now i am putting her out of rotation for a few months to recover.