How to Introduce a New Pet Rat
Rats make great pocket-sized pets for people of all ages. Because of their social nature, rats should be kept in pairs or groups so that they enjoy constant companionship. This is easy when buying or adopting rats from the same litter who have already bonded; however, creating friendships between new rats is not always simple. Sometimes, a rat owner needs to introduce a new rat (or multiple rats) to an existing rat or group of rats. By following a gradual, step-by-step process, rats can be introduced without significant injury. This hub focuses on the introduction of a new female rat, Gadget, to the resident female rat, Patches. Interactions between male rats may not be similar.
Please note: Not all rats, male or female, will take to another cage mate. There are some rats that simply want to live in their territory alone. If attempting a slow introduction through small steps does not improve the relationship or aggression either rat experiences, do not force it. Aggressive rats can cause serious harm to one another if they view one or the other as a threat.
How many rats do you have?
1. Quarantine the new rat
When acquiring your new pet rat, professionals suggest that your keep the newcomer in quarantine for one to two weeks before allowing it near your other rats to avoid the transfer of disease. What does this mean? Essentially, quarantine entails keeping the new rat in it’s own cage in a separate room without any possible contact with your other rats. This means washing your hands after handling the new rat before tending to your older residents and not swapping out items from the newcomer’s cage with anything from your other pet rat’s cage(s). Illness can spread quickly through this sort of contact. If you have multiple rats, this could result in many unexpected and undesired vet bills. Some signs of illness to watch out for include:
- lack of energy
- not eating or drinking
- discharge around nose or eyes
- noisy breathing
- excess sneezing
- excess scratching
During this period of time, you can still interact with your new rat and establish a relationship, but keep an eye on the rat’s health in the meanwhile. Is your newcomer’s nose wet, or crusted with red discharge? Rat noses are naturally dry, and wetness can be a sign of illness. Rat’s have sensitive respiratory systems and are more prone to respiratory illness than other animals. An excess of red mucus around the nose and eyes may simply be a sign of stress, especially after moving to a new environment, but can signal to illness if constantly present. Do not confuse the red mucus with blood, but keep an eye on it all the same.
Note: I did not put Gadget through the quarantine, but only because I have had my eye on her long before I purchased her at my current place of work. During this time, she had constantly been with other rats in the small animal display, and was picked on - not ill.
2. Place the cages side by side
After the quarantine period, the next step to introducing the new pet rat is placing its cage side-by-side with the resident rat cage. The cages themselves should be just far enough apart that the rats in each cage cannot reach out and touch each other (especially their tails). This allows the rats to smell and see each other and thus become accustomed to each other. Sense of smell is a big deal to rats, and is much stronger than their eyesight. Like people and other animals, rats have different personal scents; when female rats are housed together, you will often catch them “scent-marking” in different areas of the cage, especially if another rat has urinated there previously. Sometimes rats will mark you because you smell like another rat!
Did You Know?
Did you know that you can help introduce your rats by letting them run around in the other's cage? Letting each rat explore the other's smell helps it become a familiar scent, and helps them become better friends!
The rat cages should spend at least one week next to each other this way, every hour of every day. It is important that the rats become used to each other’s scents so that the newcomer smells less like an impostor and more familiar. If anything, the rats in both cages should be curious about each other, sniffing and looking at each other and sometimes showing excitement. If your resident or new pet rat is instead showing aggressive behavior or hissing, proceed through the following steps with caution. The rat may have an aggression toward other rats, and may be less likely to accept another cage mate.
3. Introduce them in neutral territory
A few days after placing their cages together, you can continue by having a play date between your resident and new rats. To minimize territorial behavior on behalf of the resident rat, the first introduction should be done in neutral territory - a place where your resident rat or rats do not usually play. A common compromise is the bathtub, but can be the bed, the couch, or anywhere else that the rats do not hang around. The bathtub was the best neutral ground for us, and should (theoretically) be harder for the rats to climb out of or escape than a sofa. When having a first play date, be sure to have something soft, like a towel, along the bottom of the tub, and plenty of tempting treats in the middle for the rats to share. Rats love treats, and eating them together is a great way for them to bond.
There is a method on YouTube called The Glove Rat that works great when introducing new rats, especially when one or both rats seem jumpy, nervous or potentially aggressive toward the other. In the video below, a woman essentially follows the rats around with a gloved hand while keeping close watch on their behavior. The idea is to deflect any negative confrontation between the two rats that has the potential to ruin their relationship, such as biting and scratching. If you get the sense that the rats are going to get into a fight of aggression, you quickly place your gloved hand between them and break it up. The glove is there for your own protection, and makes the process feel less nerve-wracking.
See the Glove Rat in Action!
It is normal during play dates for the rats to exert dominance on one another in the form of pinning each other down and forcefully grooming the other, pushing the other rat away or chasing them around. During these situations, the submissive rat will let out little “eeps” that sound low, like whispers, and simply mean that they give up. All of this is normal rat behavior - dominance is a big deal in rat colonies, and even rats sharing a cage will have scuffles over dominance. You should be concerned if a rat squeaks very loudly, or “screams” in pain, or if the rats are taking their fighting to a level you don’t like. Some signs of rat aggression include:
- pulling a rat's hair out
- biting and drawing blood
- swinging it's tail around
- hissing at other rats
Watch the play date closely and following your gut. If you think one of the rats is taking it too far, separate them. The first few play dates should be relatively short; fifteen minutes is enough for the first few days, and you can introduce them as many times as you prefer each day. As the days pass, the rats should know each other more and need to be separated less. If you have an aggressive rat on your hands, give them some space for a while before you try again.
Note: after a while, Patches (who has ninja-like reflexes and moves) learned that she can pounce out of the bathtub. If you can't keep your rats in the tub either, you can introduce them anywhere neither of them has played before - kitchen counters work, as well as tables. It's up to you.
4. Introduce them in familiar territory
Once you feel your new and resident rats are making progress, you can start putting them together in familiar territory - a place where the resident rat likes to play on occasion. This is different from the previous step because your resident rats will feel partially territorial about their play date location. This place can be the bed, the sofa, or anywhere your resident rat might consider their own. The interactions between the rats here may be more tense than in neutral territory, so having keen eyes and using a gloved hand are very important here. Your resident pet rat may feel the need to guard her territory, and more dominance fights may break out than expected. Be sure to watch that neither rat is injured or overly aggressive toward the other; if the behavior escalates to a violent level (or if you feel the need to separate them), end the session for a little while and give it another try later.
Tip: If play dates in the resident rat’s territory aren't going well, take a step backward and have the sessions on neutral ground again. You can repeat this until you feel the rats can move up to the resident’s territory again, as many times as you feel necessary. Depending on your rats and their personalities, this step can be simple or take a few tries.
5. House your rats in the same cage
When your new and resident rats have bonded enough to share the same cage, you can either put them in a brand new cage, or move them into one of the cages either rat has been living in during your introductory phases. It is more economical to move them into a preexisting cage, but this step involves a lot of cleaning, rearranging, and time. It is best to complete this step on a day when you plan on being home and can monitor the rats, as well as in the morning when your rats are sleepiest.
Note: For this step, I cleared off the bed and let the rats play while I cleaned, having a towel, play tube, toys and treats on-hand to keep them occupied. I decided to house both rats in Patches' cage, knowing that I would need to clean the smell out entirely and make it seem new and unfamiliar.
You’ll need to clean the cage from top to bottom, throwing out all the old bedding and food. Use a pet cleaner from the store that both cleans and deodorizes the cage, and be as thorough as possible. After wiping down the entire cage and any other objects (such as a running wheel or an igloo that you plan on keeping in the cage), rearrange everything. If you have a multilevel cage, move the shelves around. Change where the food and water are located, as well as any detachable ledges or other objects. If you have hammocks like my rats do, wash them and re-position them. Essentially, the cage needs to look new to both the resident rat and the newcomer. It cannot smell like the resident rat, or she will defend it like it is her territory. It helps to disorient the resident rat by adding new toys and accessories to the cage that neither rat has seen. Once this is all done, you can let the rats explore.
As with the play dates, expect more dominance scuffles started by either rat. If the introductory process has gone well, the new cage mates will take to each other eventually, but at the very least behave around each other. The struggle for dominance will always be there, as one rat will always seek to be dominant in their surroundings. Wrestling and boxing is a common way that rats like to play, so don’t be too concerned unless you spot any injuries or if a rat vocalizes her pain.Remember: In the end it comes down to your gut. If you feel the rats aren't being friendly, then maybe they need some more time apart. The truth is, most rats enjoy companionship and, over time, can become best friends.
Note: As of the present date, Patches and Gadget have been living together for over a year, and act like new friends. Sometimes Patches needs her space, but the cage is big enough for them to be apart when they want to, and be together, too.