When Seamus first encounters the Hemingway Museum, there is a cat behind him in the courtyard. While in Cuba, Hemingway became enamored with cats, keeping dozens of them on the property. The cats on the Key West property are direct descendants of those same cats.
The show's creators were forced to change the direction of the show. Originally Seamus was supposed to stay a millionaire, and the show would center around his attempts to become a writer.
A lot of the cats are six toed. Hemmingway collected six toed cats.