Rats, the pet equivalent of potato chips (you know, "no one can *have* just one!). Somewhere along the line almost every rat owner is faced with the task of integrating one rat with another or with a group. This can be difficult and harrowing stuff, but it's to be hoped that the following information will help make this transition a bit easier.

By the way, a quick word about solo rats. Those with the most rat experience agree almost universally that a rat with a same-species companion is happier than a rat without such a companion. My own experience has substantiated this. I won't even place a baby in a home where it will be the only rat.

Another important note: All newly purchased/acquired rats should be quarantined for a bare minimum of 2 weeks (a month is better), preferably in an area that does not share the same air supply (another building, if possible, or a distant room with the door closed). The reason for this precaution is to avoid exposure of your original/main group of rats to any diseases which the new rat may be carrying. The results of ignoring this precaution can be EXTREMELY tragic, up to and including bringing in SDA virus, which can kill many of your rats. Also realize that SDA can be carried on your clothing--feed/handle your original rats first, THEN the quarantined ones.

Now to the guidelines. These are arranged in order from the most careful and stringent set of procedures to the most casual of introductions. You must be the judge and decide how careful to be. In general, introducing adults warrants more caution than introducing immature rats. Also, introducing males is more difficult than introducing females, except in babyhood.

MOST STRINGENT:

After quarantine, cage the rats next to each other so they can smell each other but not touch each other. Put washcloths in both cages and switch them every day (replacing them when necessary for cleanliness). These measures allow the rats to get used to each others' scents. After a week, anoint both rats (above the nostrils and on the lower belly) with vanilla extract or stinky perfume to confuse their ability to distinguish things by scent. Then place both rats into a bathtub or on a large table too high for them to want to jump off it. Remain with the rats and observe their reactions. It is NORMAL if they posture, puff up a little, flip each other over to sniff each other's bottoms, or engage in "power grooming" (dominance grooming--the groomer pins the groomee, who usually squeaks, and thoroughly grooms a small area of the groomee just to show who is the dominant rat). Have a large towel on hand to separate them if they begin seriously fighting (you will know because they will become a rolling, biting mass of ferocity). DO NOT LEAVE THE AREA. If this first meeting proves successful (no serious injuries, no one seeming really intimidated), you can repeat the above procedure once or twice a day for 20 minutes at a time. After a week of successful meetings, give the prospective group cage an extremely thorough cleaning, washing the cage itself and replacing or scrubbing everything in it. Putting vanilla here and there in it is also a good idea before putting in new litter. Then, after a successful playtime, put both (all) rats in the cage. Oh, and make sure to provide two water bottles and two food dishes. This way the less dominant rat cannot be prevented from getting access to food or water. Then, stay within earshot of the newly integrated rats for a minimum of 8 hours (if the cage is in your bedroom and you are a light sleeper, intro near bedtime and being ready to get up and separate the rats should work). NOTE: No matter how sweet and friendly your rat is, if it feels it is defending its territory it will almost certainly bite you if you get in the way when it is going after the "invader". NEVER TRY TO SEPARATE FIGHTING RATS USING YOUR BARE HANDS. To do so is to invite a very serious bite injury.

If the rats fight despite these precautions, you might want to reconsider introducing them. Some adult males simply refuse to accept new rats. If you feel strongly about trying again, it's a good idea to wait a week after the unsuccessful first meeting, and try again in a different location (table instead of tub, for instance) and with a different masking scent (vanilla instead of perfume, for instance) to avoid predisposing the rats to repeat their initial reactions.

Also, it can be helpful to only give treats during introduction time, when the new rats are together. If the rats can come to associate good things with the time they spend together, this will encourage them to accept each other.

MODERATELY STRINGENT:

As above, except skip the washcloth step and begin the introduction routine as soon as the quarantine is over. The other steps are the same except that if all is going well after 3 days of supervised playtime, you can clean the group cage and try them together. Still be sure to be around for a while after you first put them in the same cage--sometimes they will tolerate each other for a while and then begin to fight after 2-3 hours.

SOMEWHAT RELAXED: Put vanilla or perfume on them. Introduce them in neutral territory. If they get along OK, clean the cage out and let them live together.

REALLY RELAXED: Skip the vanilla. Let them play together for a few minutes. If that goes OK, just put them in the cage.

I prefer to err on the side of caution when I am in doubt, especially when dealing with adult males, who tend to be somewhat territorial. I tend to use the more relaxed options when I am dealing with very young rats, who generally accept each other readily. PLEASE REMEMBER that all of these introductory measures should be used ONLY AFTER QUARANTINE! If you go to a pet shop, buy a cute rat baby, bring it home, and straightaway put it in the cage with your others, you are just BEGGING for an outbreak of illness or parasites!

Best of luck to you and your ratties!

Sarah Shuman