Werewolf territorial behavior
You raise a good point, what are the instincts that drive the territorial behavior of a werewolf? I think werewolves are similar to wolves in terms of their territorial behavior. Wolf packs rarely accept strangers into their territories. Wolf howling aid in spacing wolf populations and keeping packs separate. Werewolves are however part human, so I think this is where the werewolf, especially in human form, will judge and analyze the situation with human intelligence instead of just operating based on pure instinct.