My Mac is very, very, Alpha Cat and when I brought Ming into the house, things were very dicey for awhile. Mac was about 5 years old then and Ming was about 3 months old. Mac would get extremely agressive whenever he saw, heard, or smelled, Ming. It was horrible! It took two months before I could even THINK of allowing them to meet in the same room, with Ming in a carrier. I never gave up, but it was very hard and I had to have a ton of patience. One day, Ming slipped out of the bedroom and ran into the living room, and Mac. They fought hard and furiously for about three minutes and then they had it settled. Mac was Top Cat and Ming was his minion. To this day, 7 years later, it is still that way. Today they were sleeping together on the bed. Yeah, it willl happen.