Over the years, humans have used many types of animals to deliver mail. Delivery by dogsled was once a thing in Alaska and Canada; Alaska also gave reindeer a try. Horses powered the Pony Express, of course, and pigeons have been used to deliver messages since ancient Greece.
But cats? Cats have minds of their own. Unlike dogs, they typically don’t care about pleasing you. In fact, it seems they sometimes specifically go out of their way to spite their owners:
With all of this feline indifference and general propensity for lazing around, it makes you wonder what on earth the city of Liège, Belgium, was thinking when they hired 37 cats to deliver the mail in the 1870s. Messages were fastened around the animals’ necks in waterproof bags so the citizens of Liège and surrounding villages could easily communicate with each other. “Unless the criminal class of dogs undertakes to waylay and rob the mail-cats, the messages will be delivered with rapidity and safety," The New York Times reported.
Safety? Maybe. Rapidity? Definitely not. Though one enterprising cat made it to his destination in less than five hours, the others took up to a day to deliver the mail to their own homes—it would seem the cats were not terribly interested in relaying messages in a timely fashion. It should come as no surprise that the service was extremely short-lived.