In the gamepad’s radar, crows and rats are detected (and emit a “beep”) as if they were zombies, creating tension and apprehension.
The gamepad displays the map and the position of the zombies around you (like a radar). After an upgrade, the radar works automatically. But crows and rats will also trigger the radar and emit a “beep” that alerts the player even while there are no zombies.
This small feature allows level designers to create situations where a player expects zombies hidden behind a corner a as a door opens, but without actually placing enemies. This keeps players on edge, and can be adapted in other survival horror games.