Signs of chinchilla's fighting?

[GabonicaGracy]

I'm not sure if my two boys are getting along anymore. I haven't seen any outright fight. However Laurance has been having tufts of loose fur around his ears/neck and at first I thought he was shedding, but it's been a little too long in my opinion for that one spot to still be shedding.
He also hasn't been acting like himself. Normally him and his 'brother', Lafayette, will greet me at the door of the cage excited to come out. Laurance hasn't really been doing that and just kind of watches me/sits towards the back of the cage. Tonight when I let them out, there was a scuffle(I messing with something in the room for a minute) that had Laurance dart across the room like a madman with Lafayette following.
Also on a side note, my sister just moved in so we've kind of been prepping things/changing things around for her and I'm not sure if that might have started to cause this. Any ideas on what I should do?
I'll probably separate them for tonight since I don't want him unhappy/uncomfortable, but I don't have a suitable third cage available at the moment, just a temporary one.

 

[Dreamlite]

If there is hair being pulled out there is tension for sure. Do you have more than one water/food spot? Sometimes they can fight over those areas. Changes in the house like your sister moving in can also trigger issues. If you are in doubt it's best to separate

 

[Cuddlebug]

Agreed, I would separate them before things get worse. You don't want to come home and find one or both inured or dead