Introducing your rats to other rats
To ensure a smooth and successful mix, rats should always be introduced on neutral territory. Placing the rats’ cages side by side rarely works; simply putting a new rat into a resident rat’s cage could prove disastrous.
Firstly allow several sessions for the rats to meet in a neutral territory such as on a sofa, in the hallway or a small bathroom. This gives the rats time to establish a hierarchy with each other and to socialise without the stress of an enclosed environment.
If the initial encounters seem promising over the first 3 - 7days, you can they try to introduce the rats to each other in a spacious cage. The cage should be cleaned and then set up with lots of interesting places and objects to explore. It’s advisable to move the cage to an unfamiliar room to complete the sensation of neutrality. A few hidey-holes will offer welcome refuges, but do make sure that you can intervene and remove the rats if a fight breaks out: you’ll find it hard to extricate a frightened rat from a large box or untangle it from a big hammock!
Friendly, relationship-building behaviour likely to be seen includes walking past each other with no emotion shown, low-pitched squeaking, sniffing each other’s bottoms, grooming each other’s face.
You may also see them standing up on hind feet next to each other or pinning each other to the ground, followed immediately by grooming and taking more interest in the surroundings rather than in one another.
Even if the signs are this encouraging, keep a close eye on your rats until they have settled.
Signs of aggressive behaviour include wagging their tails at each other, constantly pinning each other to the ground, fluffing up the coat to make them appear larger and side walking towards each other and seeking each other out and instantly fighting, resulting in high-pitched squeals, hair pulling and wounds
If this kind of behaviour persists for more than an hour, separate the rats: this particular mix is not likely to work. Fight wounds can get infected quite easily and you may need to take your rats to your vet for a check-up.
While the bond is developing, introduce a new toy each week. You should, however, avoid sudden, sweeping changes to the environment (such as a complete change of toys or a thorough clean) because this could provoke an unexpected argument and a breakdown of the bond.
Once the rats are happily bonded, continue adding toys and apparatus that will enrich their environment. The next section will give you some ideas about how to do this.