Hello, I just wanted to ask about Bianca as, unlike her sister, she is constantly moving her jaw as though she is eating -- when she quite clearly isn't. It can be very rapid and pronounced and my daughter describes it as teeth chattering, but without the noise. Again, she quite clearly isn't in a context where she would be teeth chattering (and doing so continuously). They both had a full vet check-up the other week and their diet must be well over 90% hay, as they just have a few pellets and (under the vet's instruction at that visit) no vegetables for now. Is this usual?