I was actually wondering if it might be a stress related thing simply because she's had a terribly stressful life and has dealt with ulcers (lost nearly 200 pounds this winter and spring because of them, poor dear) for a long time until we finally found something that treated them. Ofcourse I want to make sure pain isnt the problem first, but it very well could just be a way that she deals with new things. That along with the teeth clacking seems to become more prominent when I throw things at her too fast or she doesnt understand but is trying to. Its strange.
No, she isnt getting her tounge over the bit, she merely pushes it forewards under the bit and between her teeth and holds it there.