I have 3 males and one female. None are neutered. The two oldest males sometimes will get jealous of each other and fight. Mostly when the grandkids come, they fight over whos going to get their attention first, yesterday my grandkids were comeing through the door and they were fighting before they even got in the door. Now, the youngest male gets along with all of them. The trouble starts when the female is in heat. Try keeping 3 males away from a female in heat. I do need to get these guys neutered. This is a family...mom,dad,two children