Sprite.Group Property
Syntax
Group as Integer
Determines whether or not the SpriteSurface control's Collision event handler will be called when the Sprite comes in to contact with another Sprite. Sprites with a negative Group value will collide with any other Sprites (except those with a Group value of 0).
A Group value of 0 means the Sprite will not collide with any other Sprites. A positive Group value means that the Sprite will collide with Sprites of any other Group value (except 0) but not those with the same Group value.