Rat's head, bull's neck The principle of "rat's head, bull's neck" is applied when small things prevail in a fight, when the fight is in a somewhat constrained spirit. Here we must recall the method of combat, which is either a rat's head or a bull's neck. From the little things, we must suddenly move on to the big things, alternating between the big and the small. This principle is one of the most important in the Way of a warrior. It is necessary for a warrior to apply it in his daily life.