Hmmm... Are they *really* fighting?? Our two, Gwenhwyfar and Pumpkin, fight first thing in the morning, chase each other round the house, roll around kicking and biting etc. That's not bad, technically it's just kitten play still - you see lion cubs on the savannah doing it. And it does look real - they roll around with their teeth in each others' necks. So I reckon that's the first thing to sort out, if it really *is* nasty-fighting. We've always had two cats at all times, and all of them have had fights like this during morning bursts of energy...
We also had two cats who just plain didn't like each other. They still did the fighting thing, and it was never *nasty*, but more often they just kept out of each others' way once they got used to each other...
We also had two cats who just plain didn't like each other. They still did the fighting thing, and it was never *nasty*, but more often they just kept out of each others' way once they got used to each other...