Piper totally flattens herself and really gets into it when I pet her face (up and down between her eyes) as well as full body. Cocoa seems to really like both face and full body petting but he doesn't flatten himself.
I only brought Caramel home 6 days ago, so I've just been giving him time to get used to everyone/everything. Cleaning his pen, giving him fresh food and water, and just sitting close to his pen and talking to him. Each time I would clean his pen I would let him smell me and pet him just a bit, and over time it became obvious that he was beginning to relax a bit.
Well for the first time as I was doing some spot cleaning of his pen this evening he kept smelling and following my hand. So I started to pet him and he really seemed to like it. He even flattened himself. Then when I would stop he would follow my hand and press his head against it wanting more.