The GOOD news is: all five cats are using the litter box.
The BAD news is: all five cats are using the litter box.
This is good news because one of the reasons that otherwise perfectly good, healthy, lovable pets are given up to animal shelters is euphemistically called inappropriate elimination [no, Emily, you cannot have one of my kittens]. This is bad news because cat pee is noxious stuff, even when eliminated appropriately, and even when four of the five cats are weightless balls of fluff [holding nose].
bonus linky: lolcats