游戏开始就检测碰撞的原因？

#飞机碰撞检测
rest = pygame.sprite.spritecollide(self, war.enemies, False)
print(rest,111)
if rest:
   #游戏结束
   war.status = war.END
   #敌方飞机清除
   war.enemies.empty()
   war.small_enemies.empty()
   #我方飞机坠毁效果
   self.broken_down()

[<SmallEnemyPlane sprite(in 2 groups)>, <SmallEnemyPlane sprite(in 2 groups)>, <SmallEnemyPlane sprite(in 2 groups)>, <SmallEnemyPlane sprite(in 2 groups)>, <SmallEnemyPlane sprite(in 2 groups)>, <SmallEnemyPlane sprite(in 2 groups)>] 111