APAD: when the cat's away
移花接木
楼主 (文学城)
when the cat's away or when the cat's away the mice will play, are the same
In the absence of a controlling entity, subordinates will take advantage of circumstances.
"When the cat's away" exists in many cultures. But "the mice will play" is only in English.
Have a look what the mice around the world do when the cat's away