Rats are very social animals, the majority of the time introductions can be done successfully. The success rate will depend on the rats you are trying to introduce, typically speaking younger rats are easiest, then does, then bucks and usually the harder introductions are with older rats – but if you try and are patient it should be possible to come to some arrangement, even if they will not live together, they may accept free range time with one another, making life easier for you!
*There is no guarantee any introduction will work – always be prepared to house them separately for the rest of their lives.*
To start with its best to quarantine the new rats – however this will be totally ineffective unless the new rats are housed in a completely different building (not room) which very few of us have the ability to do.
Whether quarantining or not, its best to have the rats in separate cages for the first couple of weeks, so you can get to know the new rats and look for ay general ill health, its too late if you discover a disease but smaller issues can be detected and treated in this way.
If you have a large group of established rats it is probably best to have the new rats in another room, the established group may get defensive and territorial with the smell of ‘new’ rats. After a week or so it should be okay to have the rats in the same room – cages close together but not touching or not close enough for them to reach one another through the bars.
During the time the cages are close (and dependant on ages,) the established rats may hiss/puff their fur and scent mark more than usual, this is really a natural reaction it doesn’t always mean there will be trouble, however some rats just completely ignore each other at this stage.
The next best step is to swap cages for a few hours, this can be done when one group of rats is out having ‘playtime’ or whatever, just make sure there are no rats in the cage they are going to ‘visit’! E.g. new rats go in the established cage and the ‘older’ rats go in the new rats’ cage.
Keep doing this for a few days – week, until they are used to one another’s smells.
Now we can begin actual introductions, this must happen on neutral territory such as a bathroom/bath/table top etc, but it must not be the normal play area for either rat(s). It is also a good idea to bath all the rats before hand or use some kind of safe natural scent on them, such as vanilla essence.
Place all the rats (say in this instance) on the bathroom floor, have a towel and water spray handy just incase and monitor them. It is best not to have any hidey holes as if anything goes wrong, you won’t be able to intervene.
There will be scraps and tussles, they have to find their place with the hierarchy and this can only be done with physical contact, things may look nasty but usually they don’t intend to hurt one another. Just grit your teeth and bare the squeaking! It is also normal for some of the more dominant rats to grab the newer rats and pin them down/drag them around/ hiss and puff at them.
The general rule is don’t intervene unless there is blood drawn, if somebody draws bloods its best to end that session for that day and go back to stage 2.
No matter how well this stage is going, it is not a good idea to put them all in the same cage for now, its still rather early yet. Keep repeating this stage for a few days – week; twice a day if necessary.
Hopefully things are going well now, all the rats are happy to free range together and no blood is being drawn, if you still feel you are not ready then stay at stage 3 a while longer.
This is the stage where we attempt to have them all living in the same cage. Firstly the cage must be completely cleaned and all smells of previous occupants eliminated (or as close as) nothing in the cage should smell like home to the rats who were already living in it. Again bathing may be an option, the choice is yours.
Its also good to let them free range together before going back into the cage as they will be tired and will have got any early scuffles out of the way, provide plenty of hiding places and levels to run to if they need it. At this stage I would not expect any rat to be downright aggressive to the ‘new’ rat if you have carefully followed the above stages.
But be warned scuffles and scraps will be present for the next 2 weeks at least, even longer if the rats are younger since they are always causing trouble in the ranks! However if there is any blood take it right back to stage 2 and start again.
Add all rats to cage and monitor, no doubt after a few hours you’ll find them all in the same hammock sleeping!
You did it! Congratulate yourself on a job well done, all rats are living together happily, there is still the odd scuffle but that will always be the case.
Time to start thinking about the next case of GMR (get more rats)!
Like I said at the start introductions is all about patience and taking it slow, the larger number of rats you have the harder it is to introduce smoothly, if you are attempting to introduce a third rat to an existing couple then the stages may only take a week or two! You will know when it is good to move to the next stage, if you have to intervene for fighting/blood drawn then you are probably going to fast for your rats.
In my experience with does, it took about 3 weeks for them to be in the same cage, I was on stage 2 after a week since I was introducing babies and they are very submissive and none threatening to older rats. But I know some people who can just never get it right and their rats live in separate cages as a permanent thing.
Finally I must add a few words of warning:
· NEVER use your hands to separate a fight.
· NEVER just plonk new rats into a cage containing rats in it, they WILL fight!
· DO NOT introduce bucks less than 6 weeks to an adult buck, the older bucks could see them as pray and potentially kill them.