diff --git a/engine/sdl2.py b/engine/sdl2.py
index cabdf80..8e3d150 100644
--- a/engine/sdl2.py
+++ b/engine/sdl2.py
@@ -12,9 +12,9 @@ class GameWindow:
         self.width = width * cell_size
         self.height = height * cell_size
         print(f"Screen size: {self.width}x{self.height}")
-        self.delay = 50
+        self.delay = 10
         sdl2.ext.init()
-        self.window = sdl2.ext.Window(title=title, size=(self.width, self.height), flags=sdl2.SDL_WINDOW_FULLSCREEN)
+        self.window = sdl2.ext.Window(title=title, size=(self.width, self.height),)# flags=sdl2.SDL_WINDOW_FULLSCREEN)
         self.window.show()
         self.renderer = sdl2.ext.Renderer(self.window, flags=sdl2.SDL_RENDERER_ACCELERATED)
         self.factory = sdl2.ext.SpriteFactory(renderer=self.renderer)
@@ -85,4 +85,4 @@ class GameWindow:
                     self.running = False
             # Disegna qui gli sprite
             self.renderer.present()
-#            time.sleep(self.delay / 1000)
+            sdl2.SDL_Delay(self.delay)
diff --git a/rats.py b/rats.py
index eb72f6e..1b8e3a5 100644
--- a/rats.py
+++ b/rats.py
@@ -17,7 +17,7 @@ class MiceMaze:
         self.units = {}
         self.unit_positions = {}
         self.unit_positions_before = {}
-        for _ in range(50):
+        for _ in range(5):
             self.new_rat()
 
     def new_rat(self, position=None):
diff --git a/units/__pycache__/rat.cpython-313.pyc b/units/__pycache__/rat.cpython-313.pyc
index d202cc5..d749aa5 100644
Binary files a/units/__pycache__/rat.cpython-313.pyc and b/units/__pycache__/rat.cpython-313.pyc differ
diff --git a/units/rat.py b/units/rat.py
index 8729553..8eeff9e 100644
--- a/units/rat.py
+++ b/units/rat.py
@@ -7,7 +7,7 @@ AGE_THRESHOLD = 200
 SPEED_REDUCTION = 0.5
 PREGNANCY_DURATION = 500
 BABY_INTERVAL = 50
-OVERLAP_TOLERANCE = 20
+
 
 class Rat(Unit):
     def __init__(self, game, position=(0,0), id=None):
@@ -67,6 +67,7 @@ class Rat(Unit):
         self.direction = self.calculate_rat_direction()
         
     def collisions(self):
+        OVERLAP_TOLERANCE = self.game.cell_size // 4
         if self.age < AGE_THRESHOLD:
             return
         units = []