As for the crawling, she is probably literally rubbing herself on the floor to relieve the itching, although I have a Heeler that does this on command, you say 'I am going to shoot you' to her and she goes froggy, back legs out behind her and pulling herself along by her front legs, she even changes direction to follow you if you walk backwards pretending to shoot her!
I didn't teach her this on purpose, but at a show once she was lying on the floor stretching out, and I must have given her a titbit, so she tried it again and again got rewarded and now she thinks its what I want her to do. The 'shooting' bit is just to amuse any onlookers! (and me!).