PLEASE BE SURE TO READ THE QUARANTINE INFO STICKY BEFORE YOU INTRODUCE A NEW RAT TO YOUR GROUP.

[size=24px]Introduction[/size]

Just got a new rat to add to your current bunch? Maybe you have gotten a new buddy for a lone rat, or another pair for your already too-large mischief? Don't you just want to throw them in with the old rats and watch them run around and play and groom each other? Well we'll get there, but first you have to go through a couple of steps: quarantine and introductions.

When you get a new rat (Say, from the pet store, a rescue, or even a breeder) it could have any number of diseases that have not yet shown up. One particularly nasty one is called SDA, or the Sialodacryoadentitis Virus, which has wiped out entire groups of rats from shocked (and grieving) rat owners.

Even if your rat is disease free, you run a risk of your new rat not getting along with the existing rats, or the other way around. A slow, steady build up of introductions is the way to go instead of just dropping a rat in the cage and seeing what happens.

As with all of my informative rat posts, I would not call myself an expert on this topic and none of this research is truly my own. I have taken from many different sources, mostly from these forums, and merely compiled it all in one place. I have listed sources at the bottom of this post, and you can go to those places for additional information.

Also, as with my other posts, I'd like for this to become a community post. If I've missed something or you have something that you feel should be changed or added, please just reply and let me know and I will make the appropriate changes.

Information added by Jaguar:

Generally, you'll want to quarantine a new rat for about three weeks. Quarantined rats will need to be kept in entirely different airspaces - another room in the same house just doesn't cut it. If you have friends, family, etc. that wouldn't mind fostering the rat for a couple of weeks, it is really recommended that they are totally separate from your current rats. Be sure they are cared for properly and constantly watched for any signs of illnesses. Be sure to still try and handle the quarantined rat as much as possible. It is recommended that you wash your hands and change clothing after handling a quarantined rat, just to be on the safe side.

Once the long process of quarantine is over and hopefully all went well, it's time to begin introductions! The three basic steps are separate, neutral territory, and eventually together. Although it may be a long and somewhat stressful process, the more careful and patient you are, the easier it will go.

The recommended first step is placing the new rat's cage close to the existing rat's cage, close enough that they can sniff and interact with eachother through the bars, but far enough away that they cannot be nipped or hurt and can move away at any time. Don't rush this step. Also, it may be beneficial to swap the rats into eachothers' cages every once in a while, letting them explore and smell the others' territories. Once you feel they are comfortable enough to be in the same area together, it's time to move to neutral territory.

A great neutral territory is the bathtub. I've heard of other people & personally had great success doing neutral territory introductions in the bathtub. None of my rats are particularly fond of water, and placing them all in the tub with the new rattie in a small amount of water seems to make them all forget about their aggression and dominance issues and focus on trying to get out of the horrible, horrible water. Be prepared to fight off any soggy rats clinging to you to escape. Other flat, unobstructed areas such as tables and beds can work, but be very careful that one nervous rattie doesn't take a flying leap off the edge. Do this as often as possible, and return the new rattie's cage to beside the existing one in between.

When you feel that your rats are finally accepting towards the newcomer, you can move them all in together. Be sure to clean the cage very thoroughly and remove as much smell as possible. Reorganize the toys as much as possible so it seems like a new cage. You can try putting vanilla extract on all the rats to make them smell the same. Dominance aggression towards the newcomer or others is to be expected as they figure out their hierarchy. The general rule of thumb is no blood, no foul. Even if they are scrapping, pinning down the newcomer, and he is squealing like mad, let them sort it out. Generally these are just dominance fights - but watch for signs of serious fighting such as an arched back and puffed fur- then it might be necessary to temporary separate them. Do not reach towards the rats as it may result in you getting nipped - grab with a towel or gloves if possible. It will take them some time to figure out who is boss.

Of course, complications are to be expected with any introduction. Males tend to be more difficult to introduce, especially adult males to other adult males. It's recommended to introduce young ratties to old as soon as possible, as old/larger rats will likely feel less threatened by a small newcomer. If blood is drawn (i.e. bit, scratched, hurt in any way) remove the injured rat ASAP and keep them separate. Whether you want to try to get them together again is up to you, but be very careful and take it slowly. In some cases, there are rats who will never get along, and are best to be solitary. Neutering males is a possible answer to aggression/dominance issues, but is pricey and generally a last resort.

Just remember... Take it slow, have patience, and no blood = no foul! Good luck!


[size=18px]Introduction Inquiries:[/size]

Q: I just went through all that quarantine stuff and I want to see my rats play. Do I have to introduce?

A: I wouldn't have written all this if it wasn't necessary. Introductions are necessary so you don't cause too much stress (Or serious injury) to any of your rats.

Q: How old should my rat be before introducing it to others? Original post by ScootersPet

A: A rat is supposed to be five weeks old before it is separated from its mother. Since you will have gone through a quarantine process for three weeks, then your rat should be no younger than eight weeks old when you're trying to introduce it. If for some reason your rat is younger, it would be good to wait until it's at least 5 weeks old.

Q: Are any sexes more difficult to introduce than others?

A: Though every rat is different, generally introducing neutered males to females is the easiest introduction. Females to other females is the next easiest, and intact males to other males would be the most difficult. However, every rat is different so most of how well they will take to introductions merely depends on their personality.

Introduction sources (And alternatives)

The Rat Fan Club
Suite 101
Rat and Mouse Club of America

Originally written by: Cjshrader--Thanks!!