--- a/nagslang/game_object.py	Sun Sep 08 01:04:04 2013 +0200
+++ b/nagslang/game_object.py	Sun Sep 08 01:05:03 2013 +0200
@@ -716,6 +716,9 @@
         self.shape.collision_type = COLLISION_TYPE_SWITCH
         self.shape.sensor = True
         renderer = self._fix_image(outline)
+        self._collider = puzzle.CollidePuzzler()
+        self._collider.set_game_object(self)
+        self._protagonist = None
         super(HostileTerrain, self).__init__(
             SingleShapePhysicser(space, self.shape),
             renderer)
@@ -736,16 +739,16 @@
     def update_image(self, new_outline):
         self.renderer = self._fix_image(new_outline)
 
+    def update(self, seconds):
+        if self._collider.get_state():
+            if self._ticks == 0:
+                self.apply_effect(self._protagonist)
+            self._ticks += 1
+            if self._ticks > self.rate:
+                self._ticks = 0
+
     def collide_with_protagonist(self, protagonist):
-        # We're called every frame we're colliding, so
-        # There are timing issues with stepping on and
-        # off terrian, but as long as the rate is reasonably
-        # low, they shouldn't impact gameplay
-        if self._ticks == 0:
-            self.apply_effect(protagonist)
-        self._ticks += 1
-        if self._ticks > self.rate:
-            self._ticks = 0
+        self._protagonist = protagonist
 
     def apply_effect(self, protagonist):
         protagonist.lose_health(self.damage)