I have been keeping a 1.2 ratio for my breeders and just leave the babies in there until they are weaned. I put all of the babies in the same bin later and have had offspring from multiple litters together without any issues. also I have a siamese male and female plus a grey hooded female I could give you to start your colony. Let me know if you would be interested. They are all around 4 months old now and big enough to breed.