Cats are a lot like people as far as establishing and understanding ownership, and dividing up resources. If we buy a house, we clearly understand what property is our own versus what is the neighbors’ -- fence or no fence. And we know when it’s appropriate to enter our neighbor’s property and when it’s not.
If we move in with another person, as a roommate, we work out how we’re going to share our space and resources. That’s your bedroom, this is mine. We have one bathroom, and I go to work early, so I’ll take my shower at night, you take yours in the morning.
Cats are pretty much the same. The reason cats have "behavior problems" when there are multiple cats, is because we may have created an environment that violates a cat’s sensibilities. We may unwittingly put our cats in a very awkward social situation.
Cats in the wild will mark their territory, the size of which depends on the available food supply. They’ll mark by scratching, rubbing, urinating, and leaving feces. Cats will patrol their territory regularly, and remark it often. Other cats respect the property lines, and don’t mess with another cat’s domain – any more than we’d go have a picnic on our neighbor’s lawn. They will, however, timeshare certain property – without any written contracts. They work out who uses an area at this time, and who uses it at another time. It’s all very civilized.
So, when we bring a kitty home to be our pet, she comes with all her instincts. The first thing she needs to do to make this home comfortable and livable is to stake out her territory -- which may be the whole house. She will be very uneasy until every piece of furniture has a little of her own scent on it. Most of this marking will be done simply by walking and rubbing. (Cats have scent glands in their feet, allowing them to own anything they walk upon!) Hopefully, she won’t urinate or defecate outside the litter box ... but that’s another story.
Being the sole cat in your home is a very easy and comfortable life. Everything belongs to her, and being a cat-lover, you’re okay with that. Your kitty is so wonderful, you want to get another cat.
When you bring the second cat home, he enters an environment that’s clearly owned by Miss Kitty. And perhaps she’s not too pleased with this uninvited intruder. He may not be pleased either, because it’s very clear to him that everything belongs to her. Nothing in the house has his scent, so he feels like a trespasser.
This is as awkward for cats as it would be for you to go to a foreign country, be booked in a hotel room, and when you go to your room, there’s another guest already staying there. (Your booking agent thought you’d enjoy each other’s company!) You have nowhere else to go, and no choice but to share the room. It’s awkward for both of you. How you work it out will greatly depend on your personalities.
But, strangers can become friends and what’s awkward at first can become comfortable and normal. Obviously, there are many thousands of multiple-cat homes, in which all kitties get along wonderfully, and live as one big happy family!
If you live with more than one cat, and they’re best buddies, it would be interesting to observe the territories they’ve created in your home. Notice where each cat’s favorite resting place is, and see if other cats ever occupy it. Or if there’s a spot that all the cats enjoy, notice if each one uses that spot only at certain times of the day.
While we define our home visually with walls, rooms and furnishings, your cat defines it with scent. Throughout your cat’s day filled with grooming, napping, playing, stalking, climbing and observing, there is also a whole lot of patrolling going on. This is how kitty remains in charge of her domain. And you, of course, are her most prized possession – which is why she rubs against your legs every time you come home!