All the puppy books I have read say that at 5 months your puppy is equal to ten years old. He will then start to become a little different. Instead of being the obedient dog he has been, he will start to become more independent. Since Dave just turned five months old today, we haven't seen this behavior. Last night we did his Puppy Class homework. Yes, he has homework. He practiced heeling, sitting when we stopped walking, down and turning on heel. He did so well that we decided to try him on stay, then come and then go into heel position. He was almost perfect. I think we have the star of the class here. Of course, that doesn't mean he will do it in Puppy Class with all those other cute puppies to distract him. Hey, I sound like the parent who says: "But they could do it at home!" YIKES!