Is that a sign of over-stimulation usually? Mia and Summer got in a little tiff just now and afterwards Mia was sitting there just opening and closing her mouth. She does a 'teeth chatter' quite a few ways. One is purely excitement and she chatters her teeth really fast (like say I put her in a stay and then throw the ball and she really wants it- she will chatter the teeth quickly then). #2 looks like the teeth chatter but it's slow. Usually happens on a walk or just hanging out. She will usually put her head forward a bit then scrunch up her nose and open and close her mouth. Ears stay forward on this one and she appears overall relaxed. #3 is what she did now. Ears pinned back as far as she could, tense, and mouth opening and closing very slowly. Happens after a fight only. Any ideas?