I got them!

I brought home two 8 month old females today, and I introduced them to my other babies who are also girls and the same age. I put them in the bath tub and they didn't really seem to mind, just abit of sniffing nothing you wouldn't expect. Then I popped them on the sofa together and they were just sniffing about the place and eachother and now 2 of them have gone to sleep and the new comers are still bolting about the sofa. I expected fighting and abit of roughing eachother up but nothing like that has happened? Have they just accepted the new comers or have I got it all to come yet? Lol any advice would be great thank you

Do you have two cages? Or just the one?
Ours were fine until they were all in the same cage, but even then it was just some boxing, humping and squeaking, all settled very quick and snoozing together in no time.

ive got two cages at the minute, planning to get a bigger one for them all very soon. I dont want to shove them all in together just yet. They've started squeaking now and not just light grooming squeaks i mean SQUEAKS!!! i hate it, it makes me feel like such a cruel person. but saying that their all sleeping together now! All very confusing

Sleeping together is good!
Keep the cages side by side and keep up the mixing when you can, but sounds like they are pretty happy together.

I guess its only been a matter of hours. I just dont want any of them to get hurt. You can tell ive never done any intros before

Best thing if you are worried is probably to leave them in separate cages when you can't supervise, asleep or out etc.
Haven't done many myself, and all but the last two were 20+ years ago!

With female rats, it's very rare one of them would get a serious injury during intros. I rarely do introductions by the book when I intro girls, they'd usually get on great from day 1, nothing more than a bit of power grooming and humping From what you've said, everything seems to be going exactly like you'd expect. There is usually a general rule many people go by, and that is "No blood, no foul", although having said that, sometimes (especially intro'ing male rats) a little bit of blood can be expected!