The left block of stamps were inspired by a true event. It took place in 1879 in Liège, Belgium. The city fathers attempted to train 37 cats (imagine that!) to deliver mail from the central post office to outlying villages. What the cats thought about this, and what they did and didn't do, is lost in the mists of time. All we know is that the scheme didn't turn out exactly as planned.
The stamps at the right show a family of lions on the savanna.