I live in a multiple cat household. I didn't set out to do this, they just eventually, one by one found their way to my door. And I have a bizarre weakness for orange cats. My cat Isabelle is the "queen bee" or "diva" in my house. I found her in bushes as a kitten with her eyes closed, so I brought her in and bottle fed her for three weeks. We have a special bond , I think anyway, because I was the first thing she saw when she opened her eyes.
But her behavior has become increasingly difficult to live with the more cats I introduce into the home. She's spayed, but she started spraying things in the house. Which is an odor that cannot be moved unless you just burn the house down. She went in front of our moving fan and started spraying. I guess she figured she could cover more ground this way. What a mess! I sent off for a product I found in the back of Catfancy magazine. It was supposed to stop your cat from spraying, just put a few drops in the water dish daily. It did not work.
I know Isabelle feels threatened by the newcomers in the household. I've done everything possible to make her feel that her role in the house and with me is secure. But as of this writing, I have found no solution to Isabelle's spraying problem.
I also have a cat named Greg. His favorite thing to do is when everyone is sleeping, he'll relieve himself on my stove. My stove!! Where I prepare my meals! I've tried covering the stove with a towel, blocking the edge of the counter, you name it. I've finally had to start reducing Greg's access to rooms in the house. When you have muliple cats, you have multiple personalities. Cat's are so much more emotionaly complex han we ever give them credit for. When you have multiples in your home, you have to take the time to get to know every cat and his or her likes and dislikes. I've learned to spot their individual behavior and "head them off at the pass". This way you can have a better chance to make their life, and yours more enjoyable.