My big normal girl started arching recently...I was a little confused by it aswell. I just moved her into a cb-70 rack from a 41qt single tub and along with a lot more roaming, when I open her tub and stroke her back she arches up with my movement. I thought maybe it just felt good? She doesn't squirm away, just arches as I pet her like a cat leaning into your hand. Its actually pretty cute, I hope its not indicative of any illness or stress

She just shed about a 1-2 weeks ago, and isn't showing any signs of going into shed. (No pink belly/dull/blue etc)