When I was young, our family had a Siberian Husky. One peculiarity that we noticed about this dog was the way she would communicate that her water dish was empty. She would stand there and frantically paw at the bottom of the dish. It worked; since the dish was metal it would make a ruckus and we always responded to it and refilled it. Operant Conditioning Of Humans, perhaps? Or just Annoying Habit?
The winter of 1978-1979, we moved to Cedar Mountain, NC. We lived in the house of the care-taker at a little church camp. It was a fun place to live; just down the hill from the house was the lake. There were hiking trails and the camp was closed in the winter time. It was a cold year and there was lots of snow (for that area, anyway). Dad and Mom got me a sled for Christmas that year and the weather was very cooperative. Mom and I would get on the sled and go shooting down the road. A couple of times we came close to the shore of the lake! The Husky loved it when we went sledding. She would chase along behind us and in front of us, jumping over and around the sled as we went. We usually wound up in a tangle of Mom & I, the sled and the dogs, with Dad standing at the top of the hill laughing uproariously at the whole process.
The winter went on and the weather got even colder until finally the lake started to freeze. We had a couple of close calls with one of the other dogs who would walk out on the ice only to fall through and have to scramble frantically back to shore. We took them for walks daily of course, and finally we noticed that the Husky was doing something a little odd (or something else a little odd). After playing for a while, she would walk down to the frozen lake and start frantically pawing at it, just like she did with her water dish. The difference was that when she pawed at the ice on the lake it would break. Then she would calmly lean over and get her drink of water.
Oh. Mystery solved!