This strip seems to be almost everyone's favorite, as far as I know, so I'll say a few words about it.
My original idea was to have Ohforf open the wallet and find a photo portrait of the rat family. When I told my friend Gloria about this idea, she suggested that I make it even more touching, like a letter from the little rat, or something similar to those magnets that Italians sometimes have inside their cars, with a photo of the kids and the caption "Daddy don't run". It was a very good idea, because the child's drawing is a lot better than a family photo.
Incidentally, I think that this is the only episode of the comic that my mom's ever seen - and she was shocked that I'd leave those poor little rats orphaned, how cruel of me. I'd like to point out that no animals were hurt in the making of this strip. The rat is an actor and the blood is ketchup.