Fix unit position retrieval in Rat class to use correct game state

units/rat.py

@@ -77,7 +77,7 @@ class Rat(Unit):
             return
         units = []
         units.extend(self.game.unit_positions.get(self.position_before, []))
-        units.extend(self.game.unit_positions_before.get(self.position, []))
+        units.extend(self.game.unit_positions.get(self.position, []))
         
         for unit in units:
             if unit.id == self.id or unit.age < AGE_THRESHOLD or self.position != unit.position_before: