Chinchilla reintroduction?

[SirCumference]

I saw a post about a similar thing a few down from this one, but it was a different situation than the one I'm currently in, so I figured it'd be worth creating my own! Sorry for any repetitiveness!

I've had my chinchillas, Copernicus and McKinley, for just about a year now. I think they're around 1 year and six months old, because they'd been in the pet store I bought them from for quite a while. They had been caged together at that pet store for that entire time, during which time the owner of the shop and several employees assured me there had been no altercations. The two of them got along fine. I took them home and put them into the same Ferret Nation cage and that peaceful nature continued for about three months, until they hit roughly six months old. At that point they got aggressive, particularly Copernicus, and began mounting and nipping at one another. I was told by some people on this website somewhere on an earlier post (I'm sure looking through my account would find it) that it was just a result of puberty and maturing and to house them apart until such a time as they settled down. It's now about six or eight months later and they're living on separate levels of the same cage, a slab of marble placed over the entry hole to the second floor to keep them separate. McKinley has taken to pawing at the marble from his ledge, while Copernicus, the one on top, sits there and sniffs at the edges. They've both been fairly calm in other senses, so now I'm starting to think that, with the free time summer is allowing, it's a good time to reintroduce them and open the barrier to give them a larger, communal cage. The issue I have is that since they're sharing a cage (there's scatterguards all along the top level to make sure that the top one is never pelting/degrading the bottom on, for the record) that I can't do the typical 'cages nearby' setup, plus they've already had issues in the past and I'm not one hundred percent sure that they're over that.

Any tips and suggestions on how best to reintroduce them, hopefully in a manner that would minimize any damage if the two of them DO still have issues with one another, would be appreciated! Or, after the amount of trouble they've had in the past and the amount of time they've spent apart, do you think it'd be best to just leave them in their current living situations?

 

[Amethyst]

I would say, so long as they never actually drew blood when fighting in the past it might be safe to try reintros. Since you can't do side by side I would go with cage swapping and very supervised play times together. Treat them as brand new chins meeting for the first time though, don't expect them to remember and go back the way things were. Also if things go well make sure you rearrange and fully wash down the whole cage to remove all smell of one chin or the other before opening the whole cage to them both. That way the cage doesn't smell like one chin's territory or the other's, and rearranging helps to make the cage look and feel different too.

There is no guarantee they will get along again though, going from young chin to adult can cause personality changes that don't go back to the way things were. Just like a human going from kid to teen to adult may not have the same friends or siblings/former room mates may want their own rooms. I have had chins in the past that enjoyed play mates but not cage mates too, so that is also a possibility if play time works but housing together doesn't.