Civilized creatures interact with placeables in their area that have the tag "NW_INTERACTIVE" and "talk" to each other.
Humanoid races are civilized by default, so only set this flag for monster races that you want to behave the same way.
If this flag is set, this creature will constantly be acting. Otherwise, creatures will only start performing their ambient animations when they first perceive a player, and they will stop when the player moves away.
Civilized creatures with this flag set will randomly use a few voicechats. It's a good idea to avoid putting this on multiple creatures using the same voiceset.
Creatures with _immobile_ ambient animations can have this flag set to make them mobile in a close range. They will never leave their immediate area, but will move around in it, frequently returning to their starting point.
Note that creatures spawned inside interior areas that contain a waypoint with one of the tags "NW_HOME", "NW_TAVERN", "NW_SHOP" will automatically have this condition set.