I have two female cats (fixed) and then recently adopted two male (fixed) cats. They were seperated and introduced gradually for a week and then released for a few hours at a time with the girls. All went well for the first week and then it seemed like the attacks on the girls from the boys were vicious. I would seperate them and reintroduce over food and then once the food was gone, it became a battlezone. I now seperate them in shifts-boys in a room then out into the rest of the house when the girls go in their room. Within 5 minutes of being together the territorial wars are so horrible, the girls are often so frightened of the males, they pee themselves and still this has been 6 months or more. How can I get them to live safely and harmoniously without any one getting hurt? Is it even possible? help!