I've found a rescue near me that currently has 2 ten week old rat girls.
I'm really tempted to get them, and my girlfriend has agreed on it.

Currently we only have 2 girls, who are about 14 months or so.
They've never met any other rats apart from their littermates and we brought them home at 8 weeks old as just a pair. These are my first rats, so I don't know if it would be a good idea to introduce them together so I have a group of 4 or not?

How do you go about introductions too?

Sorry about the late reply.

I think it depends on your rattie girls, are they really close and well bonded? If they are, they might not be keen to accept new rats into their group, and it might just stress them out.

However if your girls aren't like that, or you think it's worth trying anyway, then they are more likely to accept the new girls while they are still young and harmless and before they become more dominant (the babies).

I've said before that in my experience, girls accept other rats better than boys accept other boys. Boys are obviously more dominant and want to be 'alpha', so your girls will probably not have those same problems.
I don't really have much advice, as I don't have a lot of experience with this. You know your girls and if you think it is worth trying, then you could let them meet after the new girls have settled in and see how it goes. Good luck.

My situation was a little bit different, my baby was alone, and I got some new young girls to be friends with her.
I let them play on the couch and they instantly fell in love with eachother. I did this every day for 4 days and then completely washed the cage / hammocks / new toys, everything, moved it all around, put in some yoghurt, and put them all in. They were awake for 3 hours then all just went to sleep.

My girls love eachother, but I wouldn't say they are really close. Outside the cage, they never play together, and it usually ends up my girlfriend holding one, me holding the other and I put out 2 bowls of food anyway, as they tend to fight over food. I went ahead and reserved these new baby girls, and they are coming on Friday (tomorrow!), I'm like a big girl all excited about the new arrivals. I'm really looking forward to seeing how they get on together - but if there's any signs of stress or aggression I of course won't go ahead with putting them together.

Thank you both for the replies.

Any update on this, Andy? Did you get new girls? Did you introduce them? I need the latest

hope everything went well Andy

Ah we didn't get them when planned as they had breathing problems going around and wanted to quarentine, turned out not to be a virus, and only 1 rat passed away from it. Seems that a few just happened to get it around the same time. Linda from the rescue is bringing them over at 4.30pm tonight, so only 20 minutes to go now!!

Lots of luck Andy, congratulations on the new additions!!

CONGRATS

Oooh good luck Andy! You make me want more rats, but we definitely have enough... let's see how long we stick to that for though!!

How are things going Andy? Hope you finally have your new girls.  

Got both of the girls and they are really friendly, settling in great. How long should I wait before I start letting them play together?

Maybe wait a week or so for the new babies to settle in.

Yay!! Glad that you've got them home.