I got a Chin about 8 - 9 months ago. For the past month or so she has started barking for no apparent reason for about 5 - 10 minutes. Usually it's in the middle of the night, but sometimes in the day time. In the day it's when she is sleeping (at least I thing she is sleeping) in her tubes. As far as I can tell it's the same bark she gets when she gets stressed. Like when we first got her, or on the very rare occasions we've had to move her cage.
Any ideas what could be causing this? She seems health, I haven't weighed her but she doesn't appear to have lost weight, and she hasn't lost her appitite.