Movements From both Sides

The System prompt about Croco killing the zombie sounded inside Nile's mind. 

After this, he was able to confirm yet another fact about the System Map detection range. 

The zombie who Croco had killed only appeared on the System Map forty meters away from them. It looks like it was not able to detect something that was not moving from afar. If it was within his sight, it is possible to detect stationary zombies or other things, but if it was the opposite, he concluded that the System Map can only detect them if they are moving.

He already had some suspicions about it yesterday as well, that's why he made sure to check if there was something inside the root cave that could endanger his life. 

After confirming such functions, Nile became even warier about his surroundings. It was not a guarantee that the system map could detect enemies around him after all.