Basics
1. A post-pubescent degu (over 8 weeks old) will not tolerate another mature degu in the place where they live (their territory) automatically. You *cannot* put two unfamiliar degus together in the same place/cage and expect them to get along. In the wild, all degus (male or female) are very protective of their group and territory, and will defend it from intruders that might threaten the group dynamics. Even a single degu will therefore be prone toward initial aggression rather than friendliness on a first encounter.
2. The introductions process cannot be rushed. If you take things too fast than any of the degus are comfortable with, you could end up setting yourself back rather than making any progress, which will end up taking you more time to correct. Always take things slowly, don't rush your degus and don't be afraid to go back a step if you think your degus are not yet ready.
3. Introducing degu pups (newly weaned between 6-8 weeks old) is a very different process than introducing a mature degu (over 8 weeks old). We'll come to this next, but be aware that it is far easier and quicker to introduce pups to an adult degu than introducing more adults.
4. The sex of the degus involved will affect the speed of introductions. A natural group for a degu in the wild would consist of a few females and only one or two males (usually who have been together from birth), so introducing female degus to males (for breeding purposes) is going to be easier than introducing adult males to other adult males. Choose the sex of the degus you intend to introduce wisely- where possible try to introduce only same-sex pups or adults as your current degu. A special point to note about introducing male pups is that you may see some change to the group structure when they become sexually mature. During this time, you could see an increase in mounting and non-serious fighting, which is due to a rise in testosterone during this time which in effect causes the male to want to improve his rank within the group. This process should not last long (a few weeks) and is rarely serious in a previously stable hierarchy. Also note that when introducing adult males, this is best done outside of breeding season (breeding season is typically between early winter-late spring each year) when males are less territorially active and more tolerant of other males. Females should not be put through the introduction process while pregnant, as the stress could trigger a miscarriage.
5. Listen for the soundsthat the degus use during introductions and watch for their behaviours, as these give you useful indications of how they are getting along. Agonistic sounds such as the 'whine', 'groan' and 'grunt' along with aggressive teeth grinding are warning signs that the degus are not happy with each other. Watch out for agonistic behaviours such as lunging, pushing and biting during this time. Friendly sounds include the 'chitter' and 'warble' vocalisations, and may be accompanied by grooming behaviour, which is a very good sign your degus are getting along well. Note that initially you may see a lot of mounting behaviour- this is perfectly normal and is just the degu way of establishing who is 'boss'. It will become less frequent once your degus have all settled in together. Once they're living in the same cage, you might observe minor squabbles and fighting such as 'boxing' and chasing; don't be tempted to intervene or separate the degus during this time unless injury has occurred- your degus will need to 'test' on another's physical attributes in order to establish their own rank in the new group. If you step in, you could interfere with this process and actually cause it to go on longer than it should.
6. You will need to prepare an area for introductions which is considered 'neutral territory' by all degus. Therefore this should be a place that is unfamiliar to all the degus and has not been previously scent marked. For this purpose, an empty bath tub is ideal, as it is has easy access and can contain the degus for a short time. You can also consider a small, open room such as the landing area of a house, to enable all degus to remain in visual contact with each other (and you!).
7. If you have to step in during an introduction session that is going badly, be very carefulabout where you put your hands! You could easily get bitten in the heat of an argument- your degu won't mean to direct the bite at you but this can hurt if you happen to get in the way. You might want to keep a tea towel on standby just in case.
8. Note that it is not strictly necessary to go through what can be a stressful introductions process in all cases. Degus are able to form a very strong bond with a dedicated owner and learn to see them as another degu and a valuable companion. Therefore if your degu has been alone for several years and you are able to spend a lot of time with them to give the attention that they need, it may be better for them not to have to endure the stress of introducing another degu. In most cases, however, degus can benefit from the company of another degu, and so the stress of the process is marginal compared to the benefit they receive at the end. Really it is up to you to be the best judge of your degu and do what is right for them.
Introducing Them
Equipment needed:
Large cage split horizontally with a mesh divider (this will be removed later); Sand bath; Vanilla essence/peppermint oil; Neutral territory area (such as an empty bathtub); Treats (such as sunflower seeds).
Step-by-step guide:
1. Where possible, you will need a cage that can be split horizontally with a mesh divider. We have had 100% success rate using the horizontal split and find it to be more effective than a vertical split or positioning two cages side by side, as it does effectively 'trick' the degus into thinking they are part of one group, and it more effectively allows homogeny of scents throughout the sections. This guide is written based on the assumption that you have a horizontal divide. Once the cage has been divided, you will need to put the single degu into the top section, and the new degu(s) into the bottom section. You must now leave both sets of degus alone (i.e. attempt no introductions) for one week. This is to allow both degus to interact through the divide and to get used to each others' presence and scents. Don't be afraid to leave it for more than a week before moving on to step 2; ideally the degus should not be spending too much time trying to interact through the divide as this will make things much easier during introductions (increased interaction means they are acting more defensively over their territory). Note that it could be several months before the degus stop acting defensively toward each other, so be patient!
2. You can now begin to change round the sections that the degus are in (note that they should not yet meet). Swap the bottom set of degus with the top set, so that their living arrangements are reversed. This will allow both sets of degus to familiarise with the scents of each other, and this also helps to change the way they view the composition of the 'group' in their minds (you're implementing degu psychology here!). You should now leave the degus in their new sections like this for a further week before moving onto step 3.
3. When you think your degus are ready, it's time to prepare the first introduction. Whatever happens, do not rush this step, as the first meeting will make a lasting impression on your degus and will be the basis of how they meet with this degu in future encounters. You will need to mix a few drops of scented oil into the sand bath, and then allow the new degu(s) to bathe in it. Now put this degu into the neutral territory zone and then allow the single degu to bathe in the same sand. You can then put the single degu into the same zone a little away from the other degu(s). Watch very carefully as the degus approach each other and give out treats as they interact to help them form a positive association with the experience. You should expect to see a little non-serious fighting, such as boxing, and some mounting; this is normal and necessary for your degus to form a new group structure and decide who is in charge. If there is serious fighting, such as a lot of chasing and/or biting and rolling around locked together, immediately (and carefully) separate the degus and return them to their separate cage sections. You will need to start from step 1 again after this. On the other hand, if all has gone well after 10 minutes, return them to the opposite cage sections that they started in, but still keep them separate. Now go to step 4.
4. The following day, repeat step 3, and watch how the degus interact. This time, wait 20 minutes before returning the degus to the opposite cage sections. This switching around is important for when you finally remove the cage divide. If all goes well, move on to step 5. If things don't go so well in your mind, don't be afraid to go back to step 3- don't rush it!
5. The following day, repeat step 4 again, and do so for the next 2-3 days. This will help reassure you that they will be safe to spend the night in the same cage section in the next stage.
6. It's the big day (or night)- time to really see how well they're getting along. You will need to repeat step 4 but then, instead of returning them to their separate sections, you should put them all into the same section. Wait for about 10 minutes just to see how they settle in; if all seems fine you can go ahead and leave them together overnight. Night time is a good time for introductions because the degus will spend most of the time sleeping. If a group cohesion is beginning to form you may see them all huddled together sleeping in the same place. If you don't think they're quite ready for the night yet, you can always leave them together for 20 minutes in one section during the day, then return them before this stage.
7. If all has gone well overnight, you should now leave them together in the same section for the following day. It is just as important to see how they function as a group during their daily tasks as when they're out playing or in the cage sleeping. If this stage goes smoothly, move on to the next step.
8. Now they're spending a lot of time together it's time to get them used to living as a group in all the sections of the cage, which will make things go smoothly when you remove the divide. You will need to move them all to the other section of the cage, and leave them there for a day. For about a week, swap them all between top and bottom sections daily before the next step.
9. Now you're ready to remove the divide. It may seem like a lot of hard work, but if you remove the divide too soon after their hierarchy has formed, you could re-set the whole thing and end up back at step 1. So now you can go ahead and let them all out in the neutral zone while you remove the divider. Make sure you keep all the other objects in the cage the same, and don't be tempted to clean the cage out before hand- the aim is to make it look exactly the same but without the division so the degus treat it exactly the same as when the division was there (i.e. as a shared group territory). Now you can put the degus back into the now whole cage, and watch them closely for the first 20 minutes. If you see any signs of aggression, put the division back and re-do step 8 just to be safe.
Introducing New Degus
Below is home to bond degus with tips of what to do and what not to do.