I had meant to blog this, but Bioephemera got there first (we even chose the same video):
There is something primally captivating about the successful reproduction of life in art or technology. The Bowes Silver Swan is a wonderful example, dating back to the 18th century. To the accompaniment of a tinkling music box, the life-size swan moves its head, preens, and appears to catch a silver fish (which is really concealed in its throat) out of the glass “stream” it rests in.
Pretty pictures of the swan and the fish at the link.