Almost a year ago now, my friend's rat gave birth and she decided to give me one. At first I admit I was kind of against it, but I took her anyway. Wound up being one of the better decisions I've made in a long time. I've developed quite a bond with the little girl.
Her name's Freya.

(her tail's much cleaner than that now)
Recently I've noticed that she's making kind of funny noises - she seems to go into these "hiccuping" fits and once in a while she makes these noises that I can only describe as "chuckling" (if you've dealt with ferrets you know that sound). It doesn't seem to be bothering her a lot - she still acts like she always does. She does have these lethargic spells, but she's always been kind of moody. But I find it disconcerting all the same. I'm worried she may have something. There's another rat in with her named Marlena that doesn't seem to have any problems at all so if Freya has something it isn't contagious.
So I guess my question is, if you've had a pet rat, have you come across this? If you have, what did you do to remedy it?
Thanks.