You are here:

Pet Rats/Introducing New Rats


QUESTION: We just got a young male rat approximately 2 weeks ago. I asked when I got him if we perhaps should have a friend for him as I had read that they are happier with friends. At the time he was the only rat available so I was unable to get a second rat that he was already friendly with. I was also told that male rats would fight and that I should not try to introduce a second rat. As I have continued my research it seems that this isn't necessarily true and I still feel that I should have a friend for our rat, Smudge. He is approximately 4 months old. Because he is young and still fairly new to us and our home, I am thinking that it would be best to introduce a second rat sooner rather than later. Can you please advise me on the best course of action? Is having a friend in the best interest of our rat? Will he be miserable if we choose not to find him a friend? Should I be in a hurry to find a second rat to make introductions as soon as possible? What is the best way to introduce the two rats?

More info that may be helpful:
I work only part time and am able to be home most days. When I do work I am gone for the entire day. Smudge bit me in one of our early introductions and this has made me skittish around him. I am working hard to overcome this however. I have 3 kids ages 12, 7 and 5. They adore Smudge and like to pet and handle him, but they will be going back to school soon after Christmas break so will not be around to spend as much time with him. We have a yellow lab who is in the house and seems interested in but not aggressive toward Smudge. I have not allowed Smudge to roam free in our home just yet, but this is the goal.

ANSWER: Hi Elyse.  After reading your questions, it sounds like you are thinking along the right lines.  Thank you for including a photo of Smudge...he is so precious :)

Your feelings about Smudge having a companion are right on the money. You absolutely, positively must get him a friend.  Even if you and your family were home all the time, you would not spend every minute with him, and at night, when the family is asleep is when rats are most active.  Leaving him alone during those hours would be solitary confinement.  He would be very lonely, sad and perhaps even depressed.  And during the daytime, when rats tend to sleep, a friend would be someone for him to snuggle with and groom during those long hours.  By no means would getting him a friend lesson his relationship with you and your fact it would make him more confident and even more social, trust me on this one.

I gather you got Smudge at a pet store, which is not the ideal place to get rats.  The best place is a reputable breeder, and next would be from a rescue, although rescues don't often have young babies.  I can help you locate a good breeder through my sources if you reply with your location (city and state or nearest large city).

One thing you didn't ask but that is important is quarantining of new rats from resident rats.  However, if you adopt from a breeder, the need to quarantine is much less.  My own breeder whom I adopt my rats from, as do all good breeders, maintains a closed rattery so diseases do not come in and the rats you adopt are not carrying illnesses.  For this reason, I personally do not quarantine and can intro my rats right away.  If you get the new boy from a pet store and you do not quarantine, then you run a risk of Smudge getting sick.  Quarantining is not easy.  Basically, you need to keep the new rat in a completely different airspace than Smudge for a minimum of 2 weeks (some experts recommend 3 weeks), which means not in YOUR house at all, not even a different room.  The best location would be a friend or family member's house who does not own rats.  In addition, it would require you to do a complete change of outer clothes and washing of extremeties after visiting the new rat at the other person's house and before you come back to yours.  Despite all this work, 2-3 weeks to wait to introduce is a long time, and both rats would be lonely for that entire time, not to mention they are getting closer to adulthood.  And as I said, the sooner you intro the better.  So a breeder is also the easier and better way to move forward.

You heard correctly that male rats can fight, but that is generally after they become adults and their male hormones go into full swing.  Rats reach adulthood at approximately 6 months of age so your Smudge is at an IDEAL age to bring him a friend.  Aggression and fighting between males under 6 months of age is rare, so you should work quickly to find a playmate for him, hopefully within the next month.  Of course, the friend should be under 6 months also and as close in age to him as possible.  Sometimes, that's not possible, so bringing in a male a month or 2 younger than Smudge should be ok.  Baby and adolescent rats WILL do a lot of play-fighting but it is generally very innocent and rarely do injuries occur.  If an injury at the young ages does occur, it won't be anything serious, just perhaps a small play bite or scratch.  Young rats never intend harm.  You may see a lot of chasing, pinning down of one rat by the other, and grooming, but this is all for fun.

Introducing young males under 6 months should go smoothly, but I still will include this link for you to read through about introductions in may help you in the future if you're doing more difficult intros.

Last but not least, I'm going to throw in my 2 cents as I always do about something I strongly believe in and recommend to all rat owners.  And that is to bring Smudge TWO new friends instead of just one.  I, and may rat owners when they first start out do not think about what I'm going to tell you, but everyone will face this situation sooner or later.  I and others often learn the hard way.  Here's why: if you one get Smudge 1 companion, eventually one will pass before the other and you will be left with one very lonely, and often very depressed rat.  If you get 2 friends, when one passes suddenly, the remaining 2 will have each other.  At this point, you adopt another friend so you will always have a threesome.  I now ALWAYS follow this rule.  Before I began doing this, I faced this sad situation twice.  Not only is the lone rat depressed (not coming out to play, sleeping a lot, loss of appetite, etc), but you are stressing about it and scrambling to quickly find a friend, which sometimes can't quickly be found.  Then there's more time added if you need to quarantine a new rat, etc. etc.  Please believe me that you won't want to go through this.  The difference between housing 2 rats and 3 is miniscule.  The cost of extra food is very little.  You may consider a bigger cage for 3, but you may already have one that can house 3 easily -- what are the measurements of your cage now and how many levels does it have (or you can send a photo of it in your reply)...I can help if you are not sure if it's big enough.  If you do adopt from a breeder, chances are good that they may have more than one male from the same litter.

Anyway, this reply was so long but I felt it would be useful information to you.  Please do send a follow up question to let me know if you'd like me to locate a good breeder in your area or help you with cage size, questions about quarantining, or anything else.  

I will leave you will this link to a Youtube video that will support what I told you.  Have a box of tissues nearby for some sweet happy crying.  Even after watching this dozens of time, it still brings tears to my eyes :)

---------- FOLLOW-UP ----------

QUESTION: Thank you so much for your excellent answer! I am more than willing to work quickly to find Smudge a buddy or two if his house is big enough. I have attached a picture. It is a 10 gallon aquarium with a wire upper level added to the top.

I am worried about the difficulty of finding a rat breeder nearby, which is why we got Smudge at the local pet shop. It is a very small pet shop located in someone's home so I thought it was better than going to PetSmart or a similar chain. At any rate, Smudge is quickly becoming socialized and is well-loved by my kids. That said, we live in Decorah, Iowa which is in the very northeast corner of the state. The nearest cities are Rochester, MN and LaCrosse, WI. Minneapolis/St. Paul is a reasonable drive, but I'm not sure how soon I would be able to make the trip. Any help you can give me in finding a breeder would be greatly appreciated and I will make every effort to give Smudge the happiest life we can!

One more question I thought of - is there any benefit to having Smudge (and friend/s) neutered? Will that reduce the chances of fighting?

Thank you again for your excellent advice and I will be very grateful for your follow-up answer.


Hi again Elyse.  I am so glad you wrote back to me.  Sorry I didn't reply sooner but I've been doing some research for you and gathering info and photos.  It's a lot of info and it's really late here right now so I have to keep this reply short.  You will be so pleased...I found a reputable breeder for you and she has young males available now!!!

Since the info I have is pretty detailed, including lots of comments and advise on housing (cage), it would be great if we could take it off-line and communicate another way.  If you have a Facebook account, find me and send me a friend request.  It would be much more efficient to communicate with you that way.  If you don't have FB then let me know and I'll reply with the info I found tomorrow.  

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.