It's a little hard to follow your posts since I'm not sure which are mice and which are rats and they do have different breeding routines and social structures. Basic stuff though with any rodent, do not put more than one male in a tank with any breedable female rodent. The males will harrass her to death, fight over her and possibly kill each other as well as injure and stress the female.

Rodents breed very quickly so what you describe is totally normal mating behaviours.

Your female rats need to be in excess of 4 months of age and 250 grams or larger to be at the right size for the most promising outcome of their first litters. Smaller than that you tend to get less viable litters and the female rat is a bit young and small to be the best breeder she can be.

Rat breeding tends to be pretty problem free, mice are another matter and have a higher tendency to eat their young, kill cagemates, etc. if they are bothered or their social structure disturbed. Best suggestion is to read through threads on the Feeder forum to get ideas how breeding is the same and different between mice and rats.