I have a female Roborovski (Robo) hamster who is about two years old. She has always been a feisty little thing. She loves her wheel (runs on it constantly) and until lately she has been a serious runner, climber, and gatherer-- doing everything hamsters ought. But lately I've been seeing a gradual change.
She's been making the strangest noises. The only way I can describe it as is a constant chirping. It's not clicking or squealing. It's a throaty chirp. Also, she doesn't seem to be grooming as much as she used to. She still grooms her belly, but the fur on her back and head looks "disheveled", like she has bed-head. When I change her bedding every week, I put her in a bare aquarium with a sandbath, which she does use, but it doesn't seem to make a difference.
I know she's been thinning out a little, and her back is slightly arched, but I attribute that to just her aging. I haven't changed her bedding, habitat, or diet, so I don't believe it's stress.
This chirping situation is alarming me and I wonder if anyone has any knowledge of what it could be?
Thanks.

Since apparently nobody had anything to say to my question, I thought I'd let anybody who might read this in the future know that the hamster died eighteen days after the symptoms were noticed.

She grew progressively weaker, would not take water, seemed unsure of her footing, and appeared dizzy. Her breathing became labored the night before I found her.

I'm sorry to hear about your loss. At two years of age your hamster was old and sadly when they start to go downhill they go pretty fast.

I realize that you're upset that your questions wasn't answered. Had I seen your question the only advice I could have given you was to go to your vet. That's really the only option any time an animal gets sick. We can do very little over the internet and can only guess what's wrong.

Once again, I'm sorry for your loss.