In Your Opinion, Should I Breed Mice, Rats, or Both?

If your gonna do it that way, you add the girls back with the male later. Rats dont attack each other like mice do. Only fighting occurs when multiple males would be in with females. They would fight over there women. But with only 3 rats, you really would be safer leaving them all together. Seperating can create stress from being taken away from its friends/family. Once they start mateing, its like they create a family. Each rat will help each other with the babies. But there are multiple ways to breed the rats so its really all up to you. Community breeding works well for me.

I vote for community breeding I tried the separation method with one of my 1.3 groups and it actually bit me in the ass once I pulled 2 moms out they gave birth then weaned off pups when I put them back in with male he wasn't having it and neither was the other female and I actually lost my 2 females

Yup. Once babies are born i never change whos living together. It disrupts there buisiness. Best thing is to setup a small group of 1.2 or 1.3 and let them do there thing. Another thing i dont do is disturb any new born babies for roughly 3-4 days. Once i cleaned a cage that had babies born 1-2 days prior and when i put them all back the parents ended up killing them. Since then i just skip the cleaning day if i know babies were just born and clean it later in the week.