i don't know how to help you ... but wanted to wish you luck.
also, don't think me rude or anything, but would you be able to take a video to see? I used to have a bird who did this all the time and it was so funny and cuute (at first i'm sure in your case until he scratched a hole in the wall .. sorry bout that)... and would like to see how a yorkie gest mad at himself.
anyways goodluck i'm sure threr will be someone who'll be able to help you!
