Which of the following is a common indicator of enemy activity?

Changes in terrain utilization and movement patterns is a key indicator of enemy activity because it reflects shifts in how the enemy occupies and maneuvers within the operational environment. When an enemy adapts their movement patterns, it often signals an intent to engage or reposition, whether for an offensive action, defensive posture, or logistical support. Observing alterations in the way terrain is used—such as foot traffic in previously unused paths or the establishment of foreign or unusual structures—can help military units gauge the intentions and capabilities of the enemy.

Improvement in communication systems and increased visibility of friendly forces may not directly indicate enemy activity, as they relate more to the capabilities of your own forces or improvements in infrastructure. Tranquility in the surrounding area may suggest a temporary lull in hostilities, but it does not provide actionable intelligence regarding enemy activities. Thus, recognizing changes in terrain usage offers more direct insight into potential enemy movements, aiding in the anticipation of enemy actions and overall situational awareness.