childs play

I am responding to Katherine's blog question "Children entertain themselves (in the broadest sense of the term) by playing games like tag and hide & seek. Child's play is certainly appreciated by most people, but is it a form of art?"
I agree with your opinion in your blog. I think that to truly appreciate art you have to understand it to a certain point. Like when you see a beautiful masterpiece, you feel appreciation towards how it makes you feel. Then later, when you discover that the masterpiece was created with rare home-made paints and took a lifetime to create, you build on that appreciation.
I think that your question belongs in the gray area because there are certain things that i personally do not know if I would classify as art or not. Example; When people create things out of nature and then let them deteriorate because of the weather. I feel like saying that creation is art would be generalizing the word too much. People make houses that get worn away after years of bad weather. there are many things made out of nature by people and if we include them all in the definition we can just about relate art to everything. I feel like there has to be a separation between nature and art. Not that they don't have similarities, it's just that a line has to be drawn somewhere. Children playing is appreciated. By calling it art based only on the fact that people appreciate it, aren't we saying that anything that can be appreciated is art? Is that true?