Cats get their tails in a twist over anything strange, especially introducing a new feline into an established cat hierarchy. Put yourself in the cat’s paws—would you share your dinner plate, toilet, and pillow with a funny-smelling stranger off the street? Proper cat integration reduces kitty stress, prevents behavior problems, and strengthens your loving bond.

In the wild, cats unable to recognize danger don’t survive and get taken out of the gene pool. Savvy felines identify anything “new” to be a potential danger, until proven otherwise. Good early socialization—when kittens learn what to trust or fear—builds confidence and makes cats more accepting of changes. But most adult felines remain cautious, especially of new housemates.

Practicing bad behaviors makes cats good at them! Cats can generalize one bad experience—feeling upset when they see the new cat—and assume future encounters will be the same. This can lead toautomatic attack (or diving under the bed to hide) at the mere sight of the other kitty, with no other provocation happening.

Cats get hissy when sensory input exceeds their tolerance threshold. The sight, sound, and smell of a strange cat can be emotionally arousing and push one or both into a “fight or flight” mode. But blocking one sense (sight of each other) reduces arousal, and can allow strange cats to tolerate each other. A cornerstone of cat-to-cat introductions includes initially separating the cats.

Felines hate interlopers trespassing on their turf. Respect your resident cat’s prior claim to territory. Confine the new kitty in a single “safe room” so the resident cat understands only part of his territory has been invaded. This soothes the new cat by providing a familiar retreat. Provide a litter box, food and water bowls, toys, scratch post and other kitty paraphernalia in the new cat’s room.

Keep the solid door closed for at least a week, but two or three weeks may be necessary before the first nose-to-nose meeting. Monitor the cats’ interaction of sniffing and paw pats underneath the door. The cats should “know” each other by scent before they ever set eyes on each other. Expect normal posturing, fluffed fur and hissing and when that begins to fade, you’re ready for the next step.

Felines identify their family group by a communal scent, shared when they groom each other and sleep together. So feed the cats at the same time, but on opposite sides of the door, to associate each other’s smell with good things. After each cat has had a meal, switch out the plates temporarily so that they can sniff the bowls and become even more familiar with each other. It’s even better when a bit of food is left, because that helps the cats identify good stuff—food—with the other animal.

After several days, give the new cat a chance to explore the rest of the house for a couple of hours. Kitties have no interest in meeting new people or pets unless they feel comfortable with their environment. Segregate current felines in another room, then open the door so the new cat has private time to cheek rub furniture, find good hiding and sleeping places, and otherwise become familiar with her new home. If you can manage it, your resident cats can be exploring the “safe room” at this time, too, to be come more familiar with the new kid.

The best way to reduce cat controversy is to provide all your cats with so much good stuff, there’s no need to fight over it. Place multiple litter boxes and feeding stations in different locations so that one cat can’t own and “guard” the facilities. Increase territory with cat trees, shelves to lounge, tunnels and boxes to hide, and toys galore.

Finally, you’re ready for a meeting. Don’t make a big deal of this, simply open the “safe room” door, stand back, and watch what happens. Allow the cats to ignore each other, meet, or otherwise interact at their own pace. Remember, the first face-to-face between cats should be one pair at a time, so if you have more than one resident cat, confine the others until a private meeting is possible. Introduce the friendliest resident cat to the newcomer first, so they have a chance to form a bond and can offer a positive example to the others.

Be prepared to stop any all-out altercations by tossing a towel or blanket over top of the wrangling cats. But allow hissing as long as the cats keep their distance. Distract them by feeding or playing a game at the same time, but on opposite sides of the room. It can be love at first sight, or may take weeks or months to accept somebody new into the family. Some cats may never accept each other. Until you are satisfied no fur will fly, keep the new cat in her safe room whenever you can’t supervise. A baby gate in the doorway allows interactions but keeps them safely separated.