diff --git a/src/model.c b/src/model.c
index 332b9a4..4e86d8d 100644
--- a/src/model.c
+++ b/src/model.c
@@ -24,11 +24,11 @@
 #include "../include/scheduler.h"
 
 #define MAX_MODEL_NUMBER 1
-#define ARROW_NUMBER 2
+#define ARROW_NUMBER 6
 #define SITE_NUMBER 2
 #define MAX_CYCLES 10
 #define MAX_THREAD 0
-#define XMAX 30
+#define XMAX 39
 #define YMAX 0
 #define ZMAX 0
 #define SPACE_SIZE (XMAX+1) * (YMAX+1) * (ZMAX+1)
@@ -153,11 +153,28 @@ static void ModelPrepareArrows(Space_t *globalDrawingSpace,
     arrowArray->size = ARROW_NUMBER; //XXX hardcoded
 
     // Creating some arrows XXX random walking
-    globalDrawingSpace->space[3].sites[1].nArrow = 1;
+    /* In each cell: the West (left) site is 0, the East (right) site is 1 */
+    globalDrawingSpace->space[1].sites[1].nArrow = 1;
     arrowArray->array[0].siteId = 1;
-    arrowArray->array[0].x = 3;
+    arrowArray->array[0].x = 1;
+
+    globalDrawingSpace->space[2].sites[0].nArrow = 1;
+    arrowArray->array[1].siteId = 0;
+    arrowArray->array[1].x = 2;
+
+    globalDrawingSpace->space[3].sites[1].nArrow = 1;
+    arrowArray->array[2].siteId = 1;
+    arrowArray->array[2].x = 3;
 
     globalDrawingSpace->space[4].sites[0].nArrow = 1;
-    arrowArray->array[1].siteId = 0;
-    arrowArray->array[1].x = 4;
+    arrowArray->array[3].siteId = 0;
+    arrowArray->array[3].x = 4;
+
+    globalDrawingSpace->space[10].sites[1].nArrow = 1;
+    arrowArray->array[4].siteId = 1;
+    arrowArray->array[4].x = 10;
+
+    globalDrawingSpace->space[11].sites[0].nArrow = 1;
+    arrowArray->array[5].siteId = 0;
+    arrowArray->array[5].x = 11;
 }