In the Musaeum we read: “I note that Brueghel painted on parchment a mouse with some stems of roses and insects. I wanted to call particular attention to this parchment and make it known that its value can rest on the fact that even mice in it are enjoyable to look at” In actual fact, this miniature masterpiece is not on parchment but on copper, and it is most likely the “trifle, of little import” which Brueghel mentions in a letter to the Cardinal in 1605.