We all know the adage about curious cats. But their curiosity likely stems from a cat's territorial nature (a common cause of furniture scratching). “Felines are territorial animals”, writes Dr. Marty Becker for Vet Street. “Cats always want to know what’s going on in their territory, and they probably want to make sure you don’t do anything that might attract predators.” As smaller predators, housecats instinctively bury their feces so it does not attract the attention of predators. They might just be making sure their humans do the same.
After all, your home is the cat’s territory, and that includes the bathroom. Dr. Primm writes that the bathroom is within your cat’s sphere of influence. “How dare you shut him away from his own territory?" she says, from the cat’s perspective. "You might be hoarding resources or making friends with other cats. He can only know if he checks."