I took them to the vet. Surprisingly no stitches required, but the vet did prescribe a week of medication for the injured one.

After the vet, I put them back in their usual side-by-side pens and they seem fine with each other. But I can change their setup to have them on opposite sides of the room and have a barrier between them for a while.

Should I still swap them from one side to the other (I usually have them swap sides every day or two)? Or just leave them and let them claim their side of the room?

Okay, not swapping. I’m not sure we will be able to do a complete reset, with them completely forgetting each other, though. They lived side-by-side for 5 months and are pretty used to swapping and sharing space; I just haven’t had time to do a lot of proper bonding with them. They got into a fight when I was cleaning their room and one of them found a way to burrow into the other’s space without me noticing.

When I’ve done brief bonding sessions with them before, they’ve been able to co-exist in the same space peacefully–eating, grooming, flopping. If they get too near each other and exhibit aggressive behavior, I will push them apart, though. They were making so much progress before the fight.

I haven’t done bonding sessions since the fight. I think I’ll wait at least a week for cuts to heal before trying again. Then I’ll tentatively see if we can pick up where we left off in the bonding process, or if we need to start over.

They’re separated in an L-shaped room right now, but there’s a space/angle where they can still see each other. They keep going to that space and looking. I can’t tell if this is positive or negative, since all they do is look. No aggression shown; they’re far enough away that they don’t seem threatened.