Getting Started
There’s more than one safe way to introduce rats, and the best choice often depends on their personalities and your comfort level. When you bring new rats together, introductions are an important step. A lot of people find this part stressful, but it really doesn’t have to be. There’s no single “right” way to do it because every rat and every group has its own personality. One of the most common and effective approaches is called the small space or carrier method, but it’s only one option and may not be the best fit for every situation.
The idea is to put the rats together in a small, neutral space so they can’t avoid each other. This encourages them to figure out quickly that the other rats are not a threat. It also reduces the chance of injury. In larger spaces, if one rat runs and the other chases, that’s when bites and other accidents can happen.
Rats are social animals, but they’re also cautious about newcomers. In a small, safe space, they have no choice but to interact and work out their boundaries without the constant option to hide or chase. This helps them build trust faster and learn each other’s scent, body language, and habits right from the start.
Before you start, gather a few secure enclosures in different sizes so you can move through the stages without scrambling for the right setup. Avoid cages with tall sides. You’ll begin with a small carrier or cage, for the first stage, then move up gradually, about half a size to double the space at each step. Cages can be found on marketplace by searching hamster, mouse, rat cages. Even though the cages are completely unacceptable for these species , it’s a good way to get them out of circulation. Save them for future intros.
The progression usually looks like this: small carrier or cage for the first step, a small neutral cage about twice the size of the carrier, a medium neutral cage about twice the size of stage 2, a large neutral cage twice again… I generally do four stages before final enclosure , but sometimes people add an extra enclosure between three and four to play it safe.This will depend on your group and how things are going. The prevue type cage is the last stage before their permanent cage. They need to stay at each stage 36-48 hours beyond the point where they are acting content with each other, even if things look perfect.
The final stage cage is longer before you start opening space in their permanent enclosure.
Stage 1 : The Carrier
The way you handle yourself during introductions is almost as important as how the rats behave. Rats are very sensitive to our energy and mood. If they sense you are nervous or on edge, it can make them tense too and slow things down. Go into this calm, patient, and in a good state of mind. I cannot emphasize that enough!!.
From the very first stage through the final move, avoid leaning over or hovering above the rats. This can make them feel watched or trapped and may put them on edge. Instead, sit nearby at their level or slightly to the side so they can see you without feeling pressured.
Plan to start on a day when you will be home and able to keep an eye on them, and ideally the next day too. You do not have to watch every second, but you do need to be close by in case things get tense. I like to start introductions in the morning, usually between 8:00 and 10:00 a.m. By then they have burned off some energy and are more likely to relax together.
Before you put them in the carrier, I always do a quick meet in a neutral space to check for any red flags. A table or bed works best because it is small enough that they cannot get too far apart but easy for you to reach into. I do not recommend the bathtub because it is awkward to get to them and harder to step in quickly if needed.
This quick check lets you see how they react without committing to the carrier yet.
Red flags in the neutral check are puffed fur, sideling,lunging, and immediate biting. If problems present here or you are working with an aggressive or very nervous rat, we recommend looking into the neutral space approach which we will go into at a later time. Having a seasoned rat guardian help with reading body language can be so helpful if you are new to this. Joinrats.com is a great resource for body language and tips for neutral space intros.
Acceptable signs are cautious sniffing, moving around each other,force grooming and tolerating being in the same small space.
If the neutral space check looks good, move them into the carrier. Set up the carrier with a deep layer of bedding and scatter unlimited food around so they can forage. Hang a water bottle, one on each side if possible..so theres no guarding . Be mindful of the room temperature because they will already be warm from being in close quarters, so you do not want to put them somewhere hot or stuffy. Do not start introductions in the room where the current rats live. Choose a truly neutral location to avoid territorial behavior.
As soon as they are in the carrier, they stay with you the entire time during this stage. A great trick is to keep the carrier moving.Carry it around with you outside, inside, moving your arms a bit so there is more motion. This helps break up tension and keeps them from getting too focused on each other in a negative way. If you have a driver, a car ride is a great distraction when starting intros.!!
Once you set the carrier down, stay right there with them.Let them interact, but of you see anything that looks like it is about to turn into a fight, pick the carrier up and walk around with them again.
Acceptable behaviors here are sniffing, a little humping, force grooming, light puffing, and short boxing matches.
Unacceptable behaviors are hissing, bullying, any kind of biting, or a “rat tornado” which is that fast rat on rat fighting. If you see that, separate immediately. A few things here that you will want to pay extra attention to is sideling, shoving, ear pulling .
The best signs are the rats grouping together, grooming, eating contentedly without hesitancy, resting near each other, or even grooming one another. Calm, relaxed body language is a good indicator they are settling in. It is not unusual to see one rat off on their own, and that is fine as long as the interactions are positive when they do come together.
If you began intros early in the morning and by 3 o’clock things are looking good and there’s no serious issues , you can move on to the next stage. If not, and things feel tense, they stay in the carrier longer, sometimes overnight. This first stage that’s very small can be quite stressful. I prefer to not leave them in here longer than I have to. If I feel like things are going ok, I proceed. At these early stages, the Rats stay with me even through the night.
From experience, Its best not to move them to the next stage after 4:00 p.m. By that time of day, they are gearing up for their most active period, and making a big change right before that often stirs up trouble. Sticking to earlier moves can keep things calmer and more predictable.
Stage 2: Small Cage
If everything has been going well in the carrier, you can move them into a space about twice the size. Bring the same bedding from the carrier so their scent follows them. Keep the layout simple. We won’t be adding any furniture at this stage .Offer water and scatter food so there is no competition. Remain here for 36-48 hours beyond the point of them looking settled and content .
Stage 3: Medium Cage
If everything has been going well, move the same bedding into the next size enclosure so their scent follows them. Add more bedding now and keep it nice and thick. Aspen works well for all stages because it is safe, absorbent, and easy to clean.
You can add one or two tight flat hammocks only. Tight means about the size of a dinner plate, stretched so they do not sway or shift when the rats climb on them. Avoid doubles, triples, or pouch style hammocks. Loose or swinging hammocks can make the rats feel unsteady and that can put them on edge and increase tension. Place hammocks close together so they can rest near each other. Only add a second hammock if one hammock is too small for everyone to fit comfortably.
You can also add a flat litter box with low edges, so no one can get trapped behind at this stage. Keep the layout simple. Keep water easy to reach with a bottle on each side and continue to scatter feed so there is no reason to compete over food. Adding a chew hanging toy or two at this stage is acceptable.
Stay watchful. A little testing is normal, but it should settle quickly. Good signs include resting near each other, grooming each other, grooming themselves, eating, and drinking. All of the rats curled up together in the same hammock is an especially big win. If you see chasing that escalates, hissing, biting, or a rat tornado, step in and move them back to the previous stage.
Remain here for a minimum of 36-48 hours beyond the point where they’re acting perfectly content with one another.
The hammocks you add at this stage should remain with them for the rest of the introduction process so their scent and sense of comfort carry over as they move into larger spaces.
Stage 4 : Prevue 528 or Similar
If everything has been going smoothly in Step 3, you can move to the prevue stage. Bring all of the bedding from the last cage with the rats so they still have their familiar scent. Keep the bedding nice and thick so it stays comfortable.
At this stage you can slowly start adding a few enrichment items one at a time, not all at once.Things like lava ledges, bridges, and other safe things they can climb on. Chew toys and foraging toys do well here. Spread these additions out over the course of the week. Avoid anything they can hide inside or under, or anything where a rat could be cornered.
What you want to see now is the rats looking relaxed and comfortable, eating together, grooming themselves or each other, and resting near each other. It’s fine if one takes a nap alone, as long as everyone’s interactions stay calm.
Let them interact and get to know each other, but step in if you see something that looks like it could turn into a fight. If things take a turn, you can always go back a stage. Keep them in the prevue for at least a week after things feel settled before moving to their final home.
Out time during introductions is controversial in the Rat world. Many believe that the Rats should be cohesive and starting to bond and getting along well in their permanent cage before they are allowed such a large amount of space. Others believe that giving a short break to a rat that is shutting down or a rat that is wound to tightly helps to blow off steam. It is never recommended to do group out time while in introductions.
Step 5: Final Move
If everything has been going smoothly and there are no red flags, you can move the rats into their final home. The timing for this stage varies. A week in the previous stage is the general guideline, but some groups may need to stay there much longer. Always let the rats behavior guide you.
When moving into the final enclosure, keep things simple for the first few days. If you have a single Critter Nation, set it up with the deep base, a bridge, water bottle, litter box, and one flat hammock. If you have a double Critter Nation, you can reduce the height of the enclosure by using the two short shelves and the flat pan that came with the cage, placed toward the center or slightly above. You will open up more space as time goes by and they are beginning to bond.
Add one flat hammock big enough for all the rats to share. If one hammock isn’t enough, you can use a second, but keep them close together. It’s best at this stage to also avoid double triple or pouch style hammocks.
Only use a portion of the old bedding so they still have familiar smells, but replace the rest with clean bedding. This is also a good time to put in clean hammocks so the rats are not sitting in urine soaked fabric, which can contribute to respiratory infections.
Over the next several days or weeks, slowly start adding bridges, lava ledges, and other climbing options. Avoid any items they can hide in or under where another rat could be cornered. Go slowly. This is the stage where problems are most likely to pop up because of the extra space.
At this point, you might be feeling confident and paying less attention, but keep watching closely. If you can, set up a camera like a Blink or Blurams so you can check on them when you are not right there. If you see chasing, scuffles, bullying or other signs of tension, slow down and remove new items. If you see more serious issues like hissing, biting, or tornadoes, go back to the last stage where everyone was calm.
Even when things are going well, remember it can take months for rats to fully bond. Getting along in the cage is a big deal and great but becoming true friends takes time.
Common Mistakes to Avoid:
Rushing the process is probably the biggest reason introductions fail. If things are going well, it can be tempting to move forward too quickly, but that often backfires and causes setbacks. Skipping stages is another big one. Every step in the process serves a purpose, so it’s important to follow them in order.
Changing too much at once can also cause problems. Adding too many hammocks, hides, or climbing areas too quickly can make it harder for the rats to settle in together. If you do add something and notice more tension, take it back out.
Not supervising closely enough is another mistake. Even when things seem calm, it’s important to keep watching for changes in behavior. The first couple of weeks after the final move are especially important, because this is when conflict can present itself.
And finally, not going back a stage when needed. If you see chasing that escalates, hissing, or fights that don’t break up quickly, it’s better to go back to the last stage where things felt safe than to risk a serious injury.
These are just guidelines. There are many different ways and tweaks when doing intros.
If you would like help or have additional questions with the process, you can reach out to us at Oregonsmallanimalresources@gmail.com