We took our Yorkie to a frozen lake to watch boat races. I let her out of her carry bag for a bit and she discovered holes in the ice left by ice fisherman. The first hole she just sniffed and looked into, after that she must have thought they were puppy potties. Every time she saw one she headed for it and had to pee on it. After awhile we knew she was just going through the motions, her bladder isn't that big. She had a blast rolling in the snow and hitting every hole in the ice all the way back to shore.
