What you said earlier in the thread, story, about the other cats missing their king, I'm not at all sure that cats do miss other cats or even know that they are gone. I think they only know the world that they are living in now and any behaviour that we might interpretate as a cat missing another cat, is probably a cat not being used to the new surroundings.
My two cats are confined to the house and front garden so they have no social interaction with any other cats. The cats are male and female and after three years of hoping they would give me some kittens, without success, I decided to have the male nuetered because my house stunk of tom cat piss.
When the tom came home from the vet the female approached him as normal but then she sensed she didn't recognise the new smell and spat at him and lashed out at him causing him to hurridly limp

off to my bedroom. She then went and sat in the front garden for three days while the tom stayed in my bedroom for the three days. Very unusual behaviour because they usualy spend the whole time running around the house together.
It took about a week before the female would behave normaly towards the male and only after plenty of spitting and lashing out.
I don't think cats can feel joy or sadness but they certainly can cause us humans to feel those emotions.
