Rule #4: Lycanthropes are not like wolves, and do not muster or gather in packs. Persons with lycanthropy should never be within immediate proximity to one another, as each lycanthrope will involuntarily and instantly change into their werewolf form and do battle. This rule trumps Rule #3.
Although werewolves are not like wolves, they do have a "lone wolf" mentality. That is to say, when they come into contact with one another they will battle as werewolves, driven by a berserker-like rage. The fight is very often to the death unless the defeated beast can escape.
There is no room for two or more werewolves within a hunting area. Too much attention is brought to them if there are too many beasts concentrated in one area; possibly explaining why lycanthropes have evolved to hate any others from entering their hunting area.
When two or more lycanthropes are close to one another they begin to feel symptoms. For example, a person afflicted with lycanthropy could be walking in broad daylight to the store when suddenly they sense something is not right. Sweat begins to collect on the brow, and their mood quickly turns dyspeptic. The closer the lycanthropes get to one another they begin to notice each other's scent. Once within several yards of each other each person will be overcome with a deep-rooted and maddening rage, quickly followed by involuntary transformation into werewolf form. The beasts will tear and bite at each other until only one is left standing, unless the weaker can somehow escape.
Hopefully this won't happen while grocery shopping or standing in line at the Post Office.