Pet Rats/Adoption


Hi Irene! I don't know if you remember me, but you helped with my two boys, Charles and Eddie. In one of the last email, you mentioned keeping rats in larger groups. Charles and Eddie are two brothers who are exceptionally close. Would adding two new rats to the cage put either the brothers or the other two rats in danger of fighting? If not, should I get male or female rats? How do I introduce them? Will they fight? Thanks again for your help with Charles!

Hi Ella, of course I remember you and your gorgeous boys!  I hope they are both doing well now.  

Unless you intend to neuter either Charles and Eddie, or spay 2 new girls, both of which is costly, I would stick with getting 2 new boys.

You will need a second cage, which can be smaller.  Perhaps you can find a used one on craigslist or just get a cheaper one for the new rats as a temporary home.  A second cage comes in handy anyway even after all rats are can be a place to temporarily house them while you clean the main cage.

If you decide to get 2 new boys who are 3 months old or less, the new boys must be kept separated from Charles and Eddie until they are 3 months old or older because your existing boys, nomatter how sweet they are, are likely to see the babies as prey and kill them.  

If you decide to get 2 boys that are over 3 months old, they can be introduced to Charles and Eddie almost right away.

It is always recommended that new rats be kept isolated from your resident rats for 2 to 3 weeks in case they carry disease or infection so that they do not contaminate your 2 boys.  Ideally, they should be quarantined in a space that is completely apart from the air system of the space your 2 boys reside in.  Perhaps a basement that is warm (as long as it does not share the same air space as your home), or at a friends or family's home where there are no other rats.  This is ideal.  Not everyone can do this however.  IF there is no way for you to do this, you can bring in your new boys and keep them perhaps in a room farthest from where Charles and Eddie reside for 2 to 3 weeks.

After the quarantine period is over, you can begin introductions.  Ideally intros should be done in a space that your current boys are not familiar with...a neutral area.  This is because rats are very territorial so if "strangers" come into their space, they may not take to it well and can attack.  Perhaps a bed, a bathroom, etc.  Ideally it should be a small area where they are all within your reach so you can stop a fight if it breaks out.  Fights can break out quickly so you need to be aware every second.  If you can wear work gloves during intros, that will prevent you from getting scratched or bitten.   I do not mean to scare you.  These are precautionary measures.  There is a good chance there will be NO fighting and they will love the new boys.

There are signs of an imminent fight you should be on the lookout for.  If one or more of the rats start getting poofy (fur standing up) or if they make foof sounds, or if they start to side kick each other, separate them for a minute or 2 and try again.  To make it easier, you may want to start with one of your rats with the newcomers and then do the other rat at a different intro time, and see how that goes.  If well, then you can do Charles and Eddie with both new boys.

Intro sessions should be kept brief at the beginning...5, 10 or 15 minutes each depending on how smoothly things are going.  They should be repeated say 2 to 4 times a day and can be made longer if things are going well.

It may take a day or a week for them to begin to accept each other so patience is a must!

Once they like and accept each other, it's time to integrate into the main cage.  IT is critical you thoroughly clean Charles and Eddie's cage to remove all their scents.  Including all bedding and toys.  Re-arrange new bedding and toys as differently as possible so Charles and Eddie think it's a new cage.  

Then allow the 2 new boys to go into that cleaned cage for a while, perhaps 30 minutes.  Then, slowly add one of your resident boys in and watch carefully.  If things go well, add the other boy and continue to monitor closely.  Hopefully, things will go smoothly and you can breathe a happy sigh.  

If you have any problems with any of this, you can write me again.  But better yet, for more timely interaction with me, find me on Facebook under my name.  My profile pic has a face shot of me and one of my ratties wearing a bday hat :)

Please keep me posted on what you decide and again, do not fear.  This is an important thing you are doing getting more companions for your boys.

PS - If there is continued aggression with one or more boys, there is a solution!  Neutering, but hopefully it will not come to that.

PPS - Oh and I found an article regarding rat intros that I have seen before.  It is from a trustworthy source, written by a long-time rat expert.  I just read this article over again and you will see that it repeats a lot of the info I've given you above.  There are a few variations and some info that I forgot to give you, so please read it for thorough info on rat intros.  Good luck and hope it all goes smoothly.  Please write me with any questions at all, or find me on FB and write me there.  

Pet Rats

All Answers

Answers by Expert:

Ask Experts


Irene Murphy


I can answer a variety of questions regarding adoption and care of pet rats throughout their lifetimes, including questions about their health and well being, temperment, diet, bedding, cages, toys, etc. I will try to answer your questions to the best of my ability in a timely manner and I have an abundant amount of resources to help me to help you with your pet rats. I love rattie pictures, so include pics with your question if you can. You may ask me medical questions, but please be advised that I am not a vet. I may use my resources to answer some medical questions, however, I will need to refer you to your local vet with medical questions that I feel I am not qualified to address.


I have been a huge rat enthusiast for many years. Since becoming a rat owner, I have educated myself in all areas of pet rats from every resource I could find including the internet, books, conversations with local exotic vets, as well as several local rat breeders.

I have a college degree but not in the area of animals. I have obtained my extensive experience and knowlege of pet rats all on my own because in my eyes, pet rats are the most interesting and fascinating creatures you can ever imagine to have as pets. I also am saddened by how mislabeled and misunderstood these amazing and extremely smart animals are by the majority, and my mission in life has become to educate and change as many people's perceptions of rats as I possibly can.

©2017 All rights reserved.