Even if you already have rats you should not get an single young rat the young rat will be scared of the new place they are going to and the introduction will be a lot worse for them. Also if all the rats are older than them they will not have anyone of the same age to play with. Just think if you go to an new place by yourself it’s very scary but if you go with an friend it’s a lot better.
Rats do not have to be related to get on you do not have to get siblings. I often have 2 litters at an time in order for new owners to have 2 totally different looking rats. Male rats can live together.
Rats like people may not always get on. But always go with the no blood no fowl rule. As long as they no blood they should not be made to stop fighting. Pinning of each other, boxing and screaming at each other is quite normal. Baby rats often scream their heads off and the other rats have not even gone near them. They can be big drama queens.
Things that don’t work and that can make things worse.
- Putting cages next to each other. (this winds the rats up they can smell the other rat but not get near to them which can make the intro later worse.)
- Vanilla estrate/washing them (you can not hide they smell the other rat will still smell it and putting it on or washing them is very stressful.
- Putting them in an large cage/with hides in. (the rats become territorial and fight more trying to protect an big space. They also hide away not wanting to get to know each other.)
The Best way
Their is various ways to do intros but I always use the carrier method. I’ve been doing it for years and it’s always worked only one time it has not and then I had that lone boy neatured and once recovered did an carrier intro again and it worked fine.
Jemma has done an great article on how to do it already personally I don’t put in do an neutral meeting first.