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The introduction process can be an important tool to avoid rat fights and aggression. While some rats will accept new friends easily, others will need work to create a harmonious colony.

Introductions can be quick, or they can take months. It's important to never give up on your rats as there are always more tricks to try. It's not recommended to leave newly introduced rats together without supervision. Follow the guide below when adding new rats to your group!


It's suggested to quarantine all new rats for 2 to 3 weeks prior to introducing them to your current rats. Keep new rats in a separate air space to avoid the transfer of illnesses and external parasites.

It's important to maintain a routine with your rats!

Stick to a routine during introductions as it makes the process go much quicker. Your rats will know what to expect and won't be taken by surprise which may lead to nervous or aggressive behavior. A routine makes it easier for everyone - you and your rats!


Will my rats accept a new rat?

The short answer is yes. Although it may take time, most rats will be able to accept newcomers.

The easiest rats to introduce are young rats, females, and neutered males.


Do I need 2 cages?

Yes! Never place the new rat into the existing cage as this may lead to fighting caused by territorial aggression. Rats are naturally inclined to defend their territory against strangers, so it's always best to have separate cages at first. The new rat's cage does not have to be large as it's not the permanent home.


What are the signs of aggression?

Aggression can be seen by both your existing and new rats. Pay close attention to these signs to avoid injuries. Puffed fur, arched back, swaying, walking sideways, or lunging. Teeth chattering can also be a sign of distress.


How do I break up a rat fight?

Rats play fight and wrestle for dominance. This often involves boxing, grooming, and squeaking. A serious fight will be preluded by the signs of aggression listed above and will result in an injury. Don't try to separate fighting rats with your bare hands. Have a towel or oven mitt nearby to help you intercept the fight. Often, the rule for rat fights is "no blood, no foul". But it's good to stop fights before they start!






Step 1

Cage Neighbors

1. Hey Stranger!

Place both cages side by side so that the rats can see, smell, and hear eachother. Make sure the cages are far enough away so that the rats can't reach each other in order to avoid bites to noses, toes, and tails. Leave the cages like this for a couple of hours at minimum, although an entire day is best.


2. Friends Borrow!

Take 1 item from each cage (hammock, fleece scrap, etc) and place it into the other cage. This allows your rats to "meet" eachother without the stress of meeting their living, breathing neighbor!


3. The Tour!

Switch the rats into the other's cage - but do NOT keep the current resident in the cage while you do this. You wouldn't appreciate an intruder in your home, and your rats don't either! Let them have some alone time stalking the other's cage.



Step 2

Neutral Territory

1. What is considered "neutral"?

Neutral territory is an area that neither rat frequents. This exludes their cage and free roam spaces. A great place to allow your rats to meet is in the bathtub, on the couch, on a table, etc.


2. Let them meet!

Now that you've chosen the neutral territory, place your rats there and allow them to meet. Pay close attention and watch for signs of aggression. Keep in mind that wrestling for dominance is very normal and will often look worse than it is. This type of play fighting is fine, but you will want to separate them if it becomes serious or if a rat becomes injured.


3. 30 minutes is ideal

If your rats can get along for 30 minutes...that is perfect!! You can leave them together for a longer period of time if that'll make you feel more comfortable, or you can move on to the next step.



Step 3


1. Clean Up!

A clean cage is very important as it removes the scent of the resident rat. Without the scent, your rat is less likely to become territorial. Ensure that everything has been scrubbed down and that you've changed the bedding. Any hammocks, food bowls, and litter boxes will need to be washed.


2. Move In Day!

Once the cage has been completely cleaned, it's time to move your new rat into the cage. Make sure that your cage is large enough to accomodate all of your rats so that they each have their own personal space. 


3. Eyes & Ears!

Watch your rats for signs of aggression. Listen carefully when you're unable to see them. A fight will likely include squeaking, shrieking, and banging around as they run and wrestle about the cage. As always, keep in mind that rats will wrestle for dominance - only break up serious fights.




Helpful Ideas

It's okay to repeat steps

If your rats fight during the Neutral Territory phase, go back to the Cage Neighbors phase. If your rats fight when you place them in the same cage, go back to the Neutral Territory phase. It's okay to repeat steps and to go back as necessary.


Don't give up on your rats

It's uncommon to find 2 rats that are incapable of getting along. Most rats, with time and patience, will accept new rats. Maintain a routine and try every trick before giving up. If you try for 2 months and are not getting good results, then it may be necessary to give up.


Neutering males helps

Males can become aggressive due to their hormones. Schedule a neuter with your exotic vet. This should take care of the issue in most cases, allowing your males to get along. Give it time for the neuter to take full effect and try the Introduction Steps again.


Don't introduce baby rats under 6 weeks old

Males and females may kill strange baby rats, so wait until your babies are at least 6 weeks old and able to defend themselves.


Step 2.5 - Free Roam Introductions

After you've allowed your rats to meet in a neutral territory, you can watch them meet in your current rat's free roam or play time space! This allows you to watch them interact before placing them in a cage. You should see signs of territorial aggression at this point - should there be any at all!


Change up the interior design of the cage

If your rat is becoming aggressive when the new rat enters the cage, change everything around. Move the food bowls and water bottles. Hang hammocks in new areas. Place ramps in new positions. Rearrange the cage so that it looks like a new and exciting place!


Bath Bonding

Most rats hate baths, and while baths aren't often necessary for rats, it can be a good choice to force bonding. Fill the tub with an inch or two of luke warm water. Add rats. The stress of the bath can be enough to bond them together.


Vanilla Extract

Dab some vanilla extract on your rats to mask their natural scent. Since both rats will smell the same, they won't be inclined to fight the stranger. Allow the vanilla to wear off naturally.


Place both rats in your lap

Let your current rat know that you have accepted the newcomer by placing them both on your lap. 


Give your rats treats

Treats are great distractions and will quickly teach your rats that there's enough food to go around. They won't have to feel threatened that a newcomer is coming to take their share of the food.


Rats WILL battle for dominance

Remember this fact! All rats - even rats that love eachother - will wrestle and fight for dominance. This often looks and sounds worse than it is. You do not have to split them apart during dominance battles.


Separate aggressive rats immediately

Spray them with water, toss a towel over them, or separate them with an oven mitt over your hand. Do not try to separate rats with your bare hands as they may attack you on accident.


Know when to give up

Introductions may take 1 day or 2 months. If your rats are not getting along after 2 months of routine introductions, it may be time to give up. If a rat is terrified of other rats, it may be best to let him or her live alone. The goal is to create a friendship and a bond, not force two rats together that do not get along.


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