Bringing New Rats Home

Once you own your first rats, it’s very likely you will want more rats in the future. Whether it’s to grow your own mischief or to fill the gap after a fur baby has crossed the rainbow bridge, there will be occasions where you will need to introduce new rats to rats already established in your home. The following is from the Introductions article on our sister rattery’s website:


If you already have rats at home, you may be wondering what the best way to introduce your new rat(s) to them is. Some people believe it is okay to simply put them into the cage right away, but this can actually lead to some serious problems. Here, we will go over some of these problems, and tips on how to avoid them and create a safe, comfortable environment for the whole furry family.

Why Are Introductions Important?

Introductions are an important step to ensure the safety of your new and current rats. If your new, or current, rats are 3 months of age or older, this step becomes even more important. Rats begin showing signs of puberty at around this age. Once they begin going through puberty, they will begin to sort out the hierarchy of their mischief. This is done by showing displays of dominance, and sometimes fighting, which is a perfectly natural behavior in the rat world.

Once the pecking order is established, any new rat that comes into the mischief may upset this order and cause even more fighting to break out. This can be especially dangerous for rats under the age of 3 months that are being introduced into a cage of mature adults, and sometimes injuries, or even fatalities, may occur. That’s why it is so important to introduce our rats properly, as the last thing we want is for any of them to get hurt.

Note: This situation may be less likely if all rats present have not yet hit puberty, but nevertheless, it is always better to be safe than sorry.

Here are the next steps that we should take in order to properly move our new friends in with our current rats.


The first thing we want to do when we bring new rats into your home is quarantine them. Unfortunately, most breeders do not serology test and this can lead to your new rats may have an underlying health problem that could be contagious to your other rats. This is why it is always important to purchase from a breeder that is upfront and honest about any and all possible health conditions found within the line that your new rat(s) came from, and preferably one that has been tested for rat born viruses via a global serology panel. However, not everyone believes honesty is the best policy and this can lead to some devastating consequences. We have seen many breeders and owners lose entire colonies because they purchased rats from breeders who were untested or kept them in dirty environments and didn’t properly breed for health, medicate, or practice honesty surrounding the health of their lineage. For this reason, it’s always better to be safe than sorry, and always quarantine new rats before introducing them into your current mischief.

To quarantine, make sure that a separate cage is set up and ready for the new rats. Keep this cage in a separate room from the current rats if possible. Also, when interacting with your new rats, ensure to wash your hands and / or change clothes if possible prior to interacting with your current mischief. Allow your new rats to remain quarantined for a minimum of 3 weeks, with the recommended amount of time being 6 weeks. This can be a great opportunity to begin the bonding process with your new rats as well.

After they have been properly quarantined and are showing no signs of sickness, you can begin the introduction process.


  • Once you are ready to introduce your new rats, thoroughly clean their cage, and move them into the same room as your current rats. Let them to settle for a few days, as this will allow your current rats to scent them and get used to the idea that there are new rats present. Do not allow them to get near each other’s cages during free roam time as this will cause them stress and frustration and may lead towards resentment between them when it comes time for introductions. Keep them in the same room, but completely separated. Also, do not stack cages on top of each other and don’t put the cages too close together.
  • After a few days, take one item from each cage [hammocks, food bowls, hideaways, toys, ropes, etc.], and swap them out with each other. This will allow both the new and current rats to start getting used to each other’s scents even further. Do this every day for at least 1 week, or until every item in the cages have been swapped, whichever you feel comfortable with. Also, when cleaning the cages, save 1/3 of the dirty bedding from each cage, mix it with the new/clean bedding, and swap it into the other cage. This further helps your rats get used to each other’s scent.
  • Once you feel comfortable, take your new rats and your current rats and allow them to have some free roam time together. If you do not have a secure, free roam area available, you can use a bathtub. Allow all of the rats to interact with each other while closely monitoring them. While they are together, sprinkle lots of treats around and play with them. This helps the rats associate each other with something good and makes the process much easier and stress free for both us, and our friends.
  • Note: Keep a towel handy just in case a fight breaks out. Should they begin fighting, simply throw the towel over the fighting rats to distract them. After removing the towel, do not immediately remove the rats as this will leave them with a negative impression of each other. Always make sure to end all interactions on a positive note, either by giving them more treats, or playing with them for a few moments before separating them. Do not flick them on the nose, yell, or otherwise physically reprimand them should a fight break out. This action will not teach the rats that fighting is bad, but will cause them to associate each other with something negative and can be a serious back pedal in progress.
  • Allow your rats to interact this way for five to ten minutes at a time, increasing the time every day until they are able to play for 30 minutes or more without issue.  
  • After your rats are able to interact during free roam for at least 30 minutes, it is time to introduce your new rats into the cage. Place your new rats in with your current rats and supervise them closely. Do this for 5-10 minutes at a time, slowly increasing the time every day until they are able to be left together for at least an hour without incident. 
  • If small fights are still breaking out, you can rub vanilla extract on the rats to help neutralize their scents and help calm everyone down.
  • Note: Some fighting may still break out from time to time, this is natural – especially as they reach maturity at around six months old. Should your rats sustain an injury from fighting, separate the afflicted rat immediately. As always if there is any doubt about the extent of your rat’s injuries, please consult with a vet as soon as possible.

That Didn’t Work

Sometimes, depending on the personality, breeding, history, and previous level of socialization of a rat, they simply will not co-habitat with any other rats. While they may be extremely happy and friendly towards us, they may be unable to live in a mischief. If you encounter this issue, it may help to take some extra time and revisit the steps listed above. If this does not help and you feel you have exhausted all options, the best thing to do may be to return the rat to the place of origin (pet store, breeder, etc.), re-home the rat (with a warning to the potential adopter of their observed behavior), or humanely euthanize them. We never advise allowing the rat to live alone in a cage, as this can cause further psychological damage to the rat. But if your rat becomes stressed and unhappy around other rats, it would be unfair to continue to try and force them to live in a cage with others as well as put your other rats in harms way. Always think about what you can do to give your rats the best quality of life possible overall.

As with all things involving our furry friends, always remember that patience is key. It is genuinely worth it for us to take our time when integrating our rats because it will help ensure that everyone remains happy, injury free, and stress free.

Source: Whispering Grove Rattery

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