How about a new skill that allows the detection of creature/NPC activity without having to spot them?
The way I picture it should work is by pressing the “detect/track” button and choose a direction. It would require you to invest a number of turns and then it would give you a message, like for instance:
-You don’t notice anything in that location. (No enemy presence or Low Skill)
-You suddenly hear the howling of a wolf. (Wolf nearby)
-You find some bear tracks on the ground. (Bear nearby)
-You can feel the unmistakable smell of rotten corpses. (Two or more zombies)
-You feel something is watching you. (Low Skill or Being tracked down or nether monster nearby)
It could be useful in forests, urban areas, underground locations, night time and other places or conditions where visibility is limited. Also, it could give you vague or wrong messages at low skill and the better you get at it, the better the detection range and accuracy of the messages.