1、窝里的蛇，不知长短。

The snake in the nest knows not its length.2、蛇钻窟窿，顾前不顾后。Snake drills holes, regardless of the front and back.3、弯扁担打蛇，两头不着实。Bend the pole and beat the snake, but not at both ends.4、蛇的本性改不了。Snakes can't change their nature.