Roman isn't trying to bite in these pictures- when Prairie dogs say hello to each other (and mine consider me one of them) they open their mouths and then they touch teeth with each other. It's a very popular greeting in dog town. Clearly he was happy to see me this morning and I was glad because he used to be quite a cranky dog... I think he's mellowing with age. Either that, or he just woke up from a very good dream!