Arthur ignores the tree, too, but I have had cats who loved to play with the ornaments. I had one many, many years ago (back when I was in my 20s) who confiscated a teddy bear ornament from the tree & put the ribbon hanger in his mouth & walked around with it like that all day, every day. It was his ornament, & he wouldn't let it go! It was really adorable! Nobody took it away from him, either -- it was quite a sight to see! (Fortunately, it wasn't breakable!)