In almost all feline flare-ups, one cat is the aggressor and the other is the defensive cat. Because these fights can be extremely violent and possibly life-threatening, even the aggressor seems to realize that it's better to avoid a dispute than to risk injury from combat.
When two cats cross paths, the aggressor frequently asserts itself immediately, often boldly approaching the interloper to sniff its tail. Through hissing, spitting, bared teeth and other intimidating or defensive postures, cats consciously and unconsciously reveal their intentions, all in slow motion.
The apprehensive cat may betray its fear in a series of defensive displays, including drawing back slowly from the aggressor. Many feline flaps degenerate into nothing more than lengthy face-offs until the defensive cat eventually breaks eye contact to flee.
While scurrying from the scene of the showdown, however, the vanquished may receive a decisive bite on the tail.