Cooper used to stick his head though the railings too. Then one day he nearly got stuck and I think that put him off!!
Your little puppy is so cute. It is strange though, Cooper looked exactly like that, but he grew so quickly, I have forgotten now and he is only about 8 months old now. I have been talking away in posts about how little hair Cooper casts - big mistake!! he now has enough hair to make about 100000 jumpers!!!!!