I found a job cleaning the elegant home of an older couple. Among other duties, I had to dust their many imported carvings and petrified collectibles, as well as pick up after their pets.
One day, I was astonished to find two ivory fossils lying on the floor beside the bookcase. I quickly picked them up, and put them back on the shelf. The next week, the same thing happened.
That afternoon, my employer came into the parlor, her faithful dog behind her. Looking around, she eyed the bookcase. "Nya," she asked the dog, "how in the world do you keep getting your bones up there?"