Definition
This idiom is used to describe a situation where people behave badly or inappropriately when the person in charge is not present.
貓不在，老鼠闆天
After the manager went on a business trip, there were many instances of late arrivals and early departures in the office; it's really a case of 'while the cat's away, the mice will play'.
經理出差後，辦公室裡出現了許多遲到早退的情況；這真是『貓不在，老鼠就開始玩』的例子。
The teacher went to a meeting, and the students in the class started making a lot of noise; it was like 'while the cat's away, the mice will play'.
老師去開會了，班上的學生開始吵鬧；這就像『貓不在，老鼠就開始玩』。
When the parents went on vacation, the kids started having parties at home; it was truly 'while the cat's away, the mice will play'.
當父母去度假時，孩子們開始在家裡舉辦派對；這真是『貓不在，老鼠就開始玩』。