Not eating/sleeping too much

Hi, I have a 2 year old female chinchilla and over the past couple of days she has become extremely quiet, she is drinking very little and not touching her food at all (she will take raisins from me and eat them though), she's also sleeping a **** of a lot and won't really come out of her nest box. She doesn't seem to be ill, she is still having sandbaths and will come and sit on my hand when i put it in her cage. Does anyone have any idea what this change in behaviour could be?



I also have 4 other female chinchillas and 1 male, although they are caged at the opposite side of the room and are never out of the cage at the same time.



Thanks :)