When playing there is no indication of where enemy's are.
So why not put an enemy detector! (Not hives or anything stationary.)
It could only be cold/warm blood?
The file picture below shows a concept art of what it would look like.
3 Stages for campaign. Small - It only shows an area which enemies are located. Not the width or depth. Just the place.
Medium - Shows a place which is safe (never underground.) still as a point - no width or depth. Big - It's medium but shows the width and depth of the safe/enemy zones.
The Big Size Is About The Core Size.
The Medium Size Is About The Circle Armour Size.
The Small Is The Same Size As Medium.
BIG - Locates the area of safety and enemies.
Medium - Locates the place of safety and the place of enemies.
small - Locates enemies.
By The Way The Concept Art Sucks. :/