I was in there the other day and there was a man and his dog. The man was choosing treats and the dog was just standing there, literally inches from the pigs' ears, and not grabbing at anything. I was waiting for him to just stretch out and take one, I could see he was interested, but no, just the occasional sniff. My dog would never achieve that level of self control.
Mind you I have a terrier whose brain is located in his stomach, it's not so much that he hasn't learned what I've taught him, it's more that he is only willing to consider cooperating if I have a visible treat in my hand. He does not live to serve and make me happy. 