英語のことわざ

When the cat is away, mice will play.

Cats are famous for chasing mice, and mice always live in fear of cats. So when the cat is not there, the mice have nothing to fear. They leave their holes and run about the house as much as they want to. In the same way, when the person in charge, for example, the manager, is not there, the employees will take advantage of this and not work as hard.