into a household of cat
s can either be done the Easy Way
, or the Hard Way
.... for you. See, cats are social animal
s (to a degree), and most of the worry
and hand wringing
related to getting your new kitten to be friends with your exist
ing cats is not needed.
In one case a friend of mine heard (where I have no idea) that the "Right Way" to get their new 8 week old kitten acclimatized to the household, which had two older cats, was to lock it in a room for a week. Folks, that is nothing but a) a Bad Idea and b) just plain mean. Luckily after a night or two of listening to her crying from behind the door they reversed their ill conceived plan and followed my advice.
I'm no expert, or doctor of catology or anything, but I have been a cat owner most of my life. My parents got Smokey when I was very young, and we got other cats as I got older. When I moved out at 20 I only spent about a year before getting my own kitten (Cornelius). A year or so after that I adopted a street cat I felt sorry for, and a couple of years after that my SO and I got a little grey fuzzball for our already-too-small apartment (this actually happened last Saturday). My integration method is not only unscientific, but it's also not guaranteed. Include standard disclaimer here.
That said, in general, domestic cats aren't going to attack or kill each other, especially a kitten. If fighting goes on it is going to happen in one of a few ways:
My personal method of kitten integration is this: Let it happen naturally. Don't force the cats together and don't force them apart. Locking a kitten in a room by itself will lead to sleepless nights for you simply because it will be lonely, scared and crying. On the flip side, don't throw your cats right in with a new kitten. They need time to sniff each other, get to know each other at their own speed.
Bring the kitten in and first go to the room where the litterbox in it. Sit down and close the door (if possible) just to give it a bit of time to get accustomed to the sights and sounds of their new environment before meeting the existing feline residents. Put the kitten in the (clean) litterbox and make sure it knows where it is and what it's for. Even non-litterbox trained kittens have some sort of instinct that lets them know what a litter box is for, and this makes a good starting point for their new home. Another Good Idea is to have a kitten box stuffed with sheets or soft towels that can make a "home base" for the kitten. If the kitten needs someplace to run if it's scared, or a place to start explorations from (depending on its fear factor) this is a good place. I think that it is best that the kitten box be the kitten's own and not be a hand me down.
By the time the kitten has gotten their bearings, the other cats will know something is up and will be meowing at the door. Let them sniff each other through a crack in the door. The new kitten I just integrated threw a tentative paw out, and my big black street cat put one in.... just seeing what would happen I guess. As long as there's no immediately obvious antagonism between the new and old residents, open up the door and stand back. Keep an eye on them just in case, but for the most part, watch and marvel how cute the new fuzzball is.
Depending on how brave they are, the kitten will prance around the house, sniffing away at things, or slowly work their way away from home base, retreating at the first loud noise or fast movement. Talk to him or her, pet them, let them get used to you as well, but try not to interfere with their explorations or meetings with other cats. While your kitten is exploring, your other cat(s) will most likely be following at a distance, not quite sure what to do, and wondering if this new thing will be here for long. Eventually they will realize they are stuck with this critter and will become friends, or at least accept them into the household. Sometimes it takes a while, sometimes it happens right away. It will happen though.
That's about it. The problems of the kitten not sleeping through the night and deciding to come and claw your butt at 3am are outside the scope of this node :) Again, I'm not an expert but I do have experience with this, and there is the possibility that what works for me will not work for you at all. Modify my methods and teachings as applicable to the personality of your kittens, cats and household.