Remove the children from each other’s line of sight. Do not discuss who started it. Just say, "We do not hit in this house. Go to your separate corners for 5 minutes."
In a child's mind, the scarcest resource isn't money or food—it is your attention . Often, fighting is a bid to see who captures the parent’s focus first. kidsfighting.com
When people hear the phrase "kids fighting," they usually think of conflict, stress, and headaches. But if we look closer, we realize that "fighting" comes in two very distinct flavors: (the emotional disputes) and Roughhousing (the physical play). Remove the children from each other’s line of sight