Watch the females health. If the male only has one female to breed with he isn't going to stop bothering her. This can lead to sickness and death and obviously a lot of stress. That is why people use groups of 1.5 or 1.4 etc etc. I personally would never have a 1.1 going, 1.2 minimum.
I have a group of 1.5 going right now, but I do it a little differently then most people. I rotate my females around depending on how many babies im going to need. Once I can tell a female is prego I move ALL soon to birth mothers in the same cage. Rats are very good are nursing other young and sharing babies. They may compete for piles, but I havn't lost a baby to cannibalism yet.
At the moment I have 3 females raising babies in one container(96 qt sterilite). Then I have my male with 2 females getting them pregnant. Then I can continue rotating if I want or sometimes Ill leave the male by himself for a few weeks to give females a rest.
Its been giving me great results.![]()