If you already have a few cats and want to add a new member of the same species, then you must learn about cats socialization. They may take some time to accept the new addition, but they will finally accept the new member.
You can successfully introduce a new cat member within ten to fifteen days. However, it is important for you to understand that cats tend to be territorial. Therefore, you will have to exercise some special care in this case. Sometimes, depending upon the temperament and individual personality of the cat, you may have to spend a longer time to help the cats socialize with each other.
People tend to love the new cat more than they love the old ones that they already had. Such an approach is going to work against the cats socialization. If your old cats start feeling neglected, they will develop a sense of insecurity and will never accept the new addition. Therefore, make sure that you still shower plenty of love and affection on them while you are introducing a new one. If the existing members feel happy and secure, they will not mind accepting the new addition to the family.
During the introduction process, while you are working on cats socialization, you had better keep the new member at a separate place. It is not very wise to put them together right from the very beginning. Make sure that the sleeping place for your new cat is far from where your current cats sleep. It can be a spare room, a bathroom, or any other small space. However, be sure to leave all the necessary things for the new cat at a separate place, such as the litter box, water, food, and even toys. After all, even the new cat should not feel neglected.
Don't Punish Your Old Cat If She Misbehaves With The New One
Punishing the old cat for misbehavior with the new one is not good, as it will make the situation worse. If you do so, you will have a harder time to work on cats socialization. It is very common to see that when you introduce a new cat, the old ones howl and hiss at the new one. Through this behavior, your cats actually want to convey a message to the new member that they are not willing to accept her in the family. The best thing you can do in this regard is to ignore such behavior.
One of the best cats socialization strategy is to use the same dish for both the current and the new cats - but at different times. This way, the cats will get used to the scent of the other cat, as it will be present in the food dish. Gradually, you can start feeding them together from the same dish. It won't work right away. So, let them take their time while you hang on to your patience. Within a week or so, you will surely achieve success.
If you still find some occasional growling or hissing, you should separate them from each other, and start the cats socialization process again.