This is what I use for rats
Each female is house individually soon as they are pregnant.
Mice they stay in the same enclosure at all time (I keep 2 mice in each tub) only the male is removed
If you have a small colony a simple setup with stand alone tubs can also be used for nursing mom. Size of the tubs will vary depending on the size or the rodents.
As for bedding
Mice and ASF I use Equine fresh at all time
Rats I use equine fresh for breeders and babies over 2 weeks old (mothers with babies under 2 weeks I use equine fresh and wood shaving)