how to introduce gerbils to each other
Care Guide

How to Introduce New Gerbils

Gerbils shouldn’t live alone as they’ll get lonely and bored. But putting two unfamiliar gerbils together straight away causes fights. This makes introducing new gerbils difficult.

Put the two gerbils on either side of a split cage, with a see-through divider down the middle. You then swap them from side to side each day. This gets each gerbil used to the other’s smell. When they seem curious and happy with each other, remove the divider. An adult and juvenile male make the ideal pair.

Introducing new gerbils should take between a week and two weeks. However, with females, it can take longer. That’s because males are friendlier with each other than females.

What You Need Before You Introduce New Gerbils

If you were to take two or three gerbils and put them together, fights would start immediately. This is a problem that many owners have experienced. That’s because gerbils are highly territorial.

Gerbil owners have come up with a way of introducing gerbils without any stress or fighting. The only problem is that for it to work, you’ll need a new cage first. You’ll also need:

  • Two water bottles
  • Two exercise wheels
  • Extra bedding
  • Extra food
  • Heavy-duty gloves, e.g. gardening gloves or leather gloves

The water bottle and extra bedding you can’t do without. If the introduction will only take a week, there’s no need for the exercise wheels. But intros can take a lot longer than that. Only with your equipment ready can you think about introducing your two gerbils.

Special Cage for Introducing Gerbils (Split Cage)

To introduce your lonely gerbil to a new friend, you’ll need a split cage. A split cage is exactly what it sounds like: a special kind of cage with two compartments.

These allow you to introduce the gerbils, but in a way that they can’t fight. It’s possible to get a split cage that already has two compartments. The dividing wall may be either glass or chicken wire. You can also make your own divider from a wooden frame and chicken wire.

The point is that the gerbils will get used to one another, but can’t fight. While gerbils are small and look cuddly, they can be vicious with newcomers. A split cage helps the gerbils like each other before you put them together properly.

Why Do New Gerbils Fight Each Other?

If you were to put the new gerbil straight in with the other, they would almost certainly fight. That’s because gerbils have strict and complex social structures, both in the wild and in captivity.

Gerbils usually mate for life. This pair will have lots of offspring. The female is capable of having six or seven pups in a litter, and sever litters per year. This group will stay with the pair until they’re old enough to go off on their own.

If a new gerbil were to try to join this group, the breeding pair would reject it. That’s because the pair want to protect their offspring. They want to ensure that their pups will survive to adulthood. To do this, they need lots of food and lots of attention.

Having an outsider join this group would reduce the amount of food and care that each of the young would get. So, the pair will often fight off any outsider that comes too close. This behavior carries on in captivity.

A newcomer can join an existing social group. But it’s much easier for two single gerbils to pair up.

How to Introduce Gerbils to Each Other

You can’t take two gerbils and put them in the same enclosure. If you do, the pair will almost certainly fight. Gerbils can even kill each other if left to fight unattended. That’s why you have to introduce gerbils the right way.

introducing gerbils without split cage

Put Your Gerbils in a Split Cage

Begin with your split cage. You can get these from pet shops, or you can also make your own with a wooden frame and some chicken wire. Whatever you use to divide the cage, it must be see-through.

Line the cage with whatever your gerbil might need, like in their regular cage. You should include:

  • Bedding on each side
  • A water bottle on each side
  • Food on each side, and perhaps a food bowl
  • A running wheel on each side (because spilt cages are usually too small to run around)

The idea is that your gerbils will be happy in their split enclosure. It should be as accommodating as their regular enclosures. If they can’t, this can have a negative effect on bonding. An unhappy, hungry or stressed gerbil won’t readily make new friends.

When your gerbils are in the split cage, don’t remove their bedding. The bedding is what holds onto the gerbils’ scent. If you remove it, you prevent the pair from getting used to one another.

For the same reason, you should avoid deep cleaning the enclosure at any time. Instead, spot clean the enclosure. This is where you remove the mess as and when you notice it. So, if you notice some poop in the split cage, take it out along with a little of the bedding.

This will prevent the mess from building up, but will allow the scent to remain. You can replace the small amount you took with a little fresh bedding each time.

Swap Your Gerbils Over

Swapping your gerbils from one side to the other consistently over this period will allow each to get used to the other’s smell.

According to the journal Science, gerbils mark their territory with the scent glands on their stomachs. The scent that each gerbil produces this way is what the other will have to get used to.

Either way, this step is an easy one to take. You carefully take each gerbil from its side of the enclosure, and put it in the other one. It’s easiest if one person takes one gerbil, and another takes the other. But you can take both at the same time.

It’s best to do this before the gerbils go to sleep. If the gerbils go to sleep somewhere they can smell the other gerbil, it gets them used to the scent even quicker.

Repeatedly swap the gerbils over the course of a week. Two or three times a day, with one time being before sleep, is the optimal amount. The two gerbils’ scents should mix, which makes each gerbil less uncomfortable with the other.

Monitor Gerbil Introduction Behavior

Throughout this process, your gerbils should become more used to one another. You can see whether they’re coming to like each other through their behavior. Positive behaviors include:

  • No visible aggression. Your gerbils shouldn’t threaten each other through the divider, e.g. by standing and staring at each other. According to the Journal of the Acoustical Society of America, gerbils also communicate through sound more than most owners realize. Aggressive gerbils squeak repeatedly.
  • Visible curiosity. The gerbils will sniff one another and spend time close together.
  • Sleeping near one another on opposite sides of the divider. Gerbil pairs like to nest together. This indicates that that’s what the pair want to do.

When you start seeing these signs, it indicates that the gerbils are comfortable together.

You don’t have to stand and watch your gerbils all day to look for these signs. Check them repeatedly over the course of the day and make a note of their behavior each time.

Remove the Divider

If you’re sure that the gerbils are acting friendly, you can introduce them properly. To do this, remove the divider in the cage. The gerbils should be comfortable with each other at this point.

Stay with your gerbils over the next twenty minutes. Watch over them and observe their behavior. There shouldn’t be any fighting, but if you notice:

  • The gerbils staring each other down
  • The gerbils making loud squeaking noises
  • The gerbils boxing one another

If so, you will need to separate them. Use your heavy-duty gloves to reach in and pick up one of the gerbils. Keep them separated, either in different tanks, or by replacing the divider in the split tank.

Also, your cage may not have a divider that can be removed. If that’s the case, you should put them in another, larger tank. While you can introduce them in only one side of the split tank, this may cause fighting. That’s because there’s not enough space.

Wait a Few Weeks

If your gerbils like each other, they will have formed a ‘clan.’ However, this clan can break up. This is known as declanning.

The first few weeks, and especially the first few days, are when declanning is the most likely. The pair may fight occasionally, and if the fights get bad enough, the pair will declan.

If fighting becomes frequent, you must separate the pair. Declanning can result in severe fights, and the gerbils can even try to kill each other. So, separate them into different tanks.

As time goes by, the pair will be more comfortable with each other. The chance of declanning diminishes the longer they’re together, although it is still possible.

What to Do If Your Newly Introduced Gerbils Fight

After separating your gerbils, you have a choice. You can either put them in separate cages, or back in the split cage with the divider.

You should be persistent and continue trying to introduce the pair. One fight shouldn’t be a significant issue. If you continue with the first steps in the process for even longer, it’s likely that the two will begin to like each other eventually.

This time, keep the pair divided for even longer. Rather than a week, keep them divided for two weeks. Continue to swap them from side to side each day so that they adapt to each other’s scent.

There are, however, some gerbils that don’t get along with others. This can be the case with solitary females. These gerbils don’t take kindly to other gerbils, and will reject any other gerbils they come across. They may also be unfriendly with their owners.

Unfortunately, there isn’t anything you can do about that. The gerbil is best kept on its own. You can keep your pair either in a split cage forever, or in separate cages.

gerbil introduction behavior

Which Gerbils Make the Best Pairs?

The introduction of two adult gerbils is difficult. Adults are more protective of both their space, and their reproductive rights. Younger gerbils get along better because they have to, as they begin life with lots of brothers and sisters.

So, if possible, you should try to introduce one younger gerbil with one older gerbil. The younger gerbil will be comfortable with the older one, as it’s used to living with older gerbils (its parents). The older gerbil won’t see the younger gerbil as a threat.

Ideally, the younger gerbil should be less than ten weeks old. And if you want to make the easiest pairing possible, pair two males. This is far easier than introducing two females. You can also introduce two pups together.

How to Introduce Male and Female Gerbils

A male and female pair isn’t recommended for beginners. That’s not because they won’t get along, which they will. It’s because a male and female pair will begin mating if paired up together.

That’s not a bad thing in itself. But what is bad is if you aren’t prepared for it. While the mating pair will take care of the pups on their own, you will need a bigger tank.

It also makes the most sense to introduce the pair when the female is in heat. This makes it more likely that the pair will become friendly. They will likely begin mating soon after they’re introduced. If you’re unfamiliar with the signs that a female is in heat:

  • It will be in heat for four day periods, roughly every six weeks
  • It will dash towards the male, before running away again
  • After it dashes away, it will stay facing away, and raise its behind

The female will most obviously be in heat during the evening, so introduce the pair then. Keep them in a split tank until you think the female is ready, then remove the divider.

Aside from that, introducing the pair is the same as described above. You may notice what looks like aggressive behavior between the two. It’s easy to confuse mating behaviors with aggressive ones.

How to Introduce Two Female Gerbils

Female pair bonds are common, but aren’t the best. If you try to introduce two females, you may find that they don’t get along well.

If the pair seem to like each other, that’s fine. But be prepared to leave them in the split cage setup for longer. That’s because it will take longer for females to become friends.

This is where you might need to put an exercise wheel in each half of the enclosure. Introducing two females can take months rather than weeks. In that scenario, both gerbils would become stir-crazy from lack of exercise.

How to Introduce Two Male Gerbils

Introducing two male gerbils to one another may be easier. That’s because a male pair get along better than a female pair. There’s less chance of fighting and rejection with two males.

You may notice that the pair become friends quickly. Leave the two in the split cage for a week as you would with any other pair. It’s likely that the pair won’t need any longer than that.

Introducing Three Gerbils

Introducing three gerbils isn’t typically a good idea. The two gerbils which are part of an established group will likely attack and could kill the third. Even if one of the gerbils likes the third, the other one may not. So, the odds of rejection are much higher.

A much better idea is to keep the existing pair as is. Then, get another gerbil and pair it up with your third one. You will end up with more tanks, but this is the only way to keep all your gerbils happy.

Of course, it is possible to have larger groups than two. Groups of up to six or seven are feasible in captivity. In the wild, groups of up to seventeen have been found. Group size isn’t the issue.

Rather, group dynamics are the issue. Big groups are formed by a pair having lots of pups. The pups will stay with their parents until they are entirely self-sufficient, and want to have their own families. These aren’t groups of random gerbils that found each other and decided to stick together.

Introducing Gerbils without Split Cage

If you can’t get your hands on a split cage, or can’t make one, you’re not out of luck. There are other ways to introduce two gerbils that don’t rely on one.

The easiest to replicate is the two-cage system. If you have one large cage and one small cage, you can put the small cage inside the bigger one. This is essentially the same as a split cage. The only difference is that one gerbil will have slightly more space.

If you can’t do that, you could put two cages close to each other. This will allow the gerbils to see one another and get used to one another. It’s swapping them over, so that they can get used to each other’s smell, which is most important anyway.

Introducing Gerbils Outside the Cage

You could also introduce your two gerbils outside of their enclosure. This allows the pair to get used to each other without being too close together in a cage.

Begin by taking them both out. Allow the pair to run around your room. The pair will explore and interact in equal measure, which is a good thing. But ensure that your room is ‘gerbil-proofed’ first, i.e. by closing entrances and exits, or by building a pen.

This will allow the gerbils to become friendly with one another in a low-pressure environment. They will each feel more secure, because they aren’t hemmed in close together. If one doesn’t like the other, it can walk away.

Imagine for a moment what your gerbil must experience when it is introduced to a new ‘friend.’ Your gerbil’s space will be invaded. It would be like a stranger turning up at your house and wanting to live in your room.

So, introductions outside the cage may help the pair befriend each other before having to live together. The only issue is that a pair comfortable outside the enclosure may not be comfortable inside one.