Explaining "When the cat is away, the mice will play"

What does it mean?

This phrase means that when authority figures or supervisors are absent, those under their supervision will take the opportunity to engage in activities they may not be allowed to do otherwise.

Tone

Origin

The phrase is derived from a medieval Latin proverb: "Dum felis dormit, mus gaudet et exsi litantro", which translates to "When the cat sleeps, the mouse leaves its hole, rejoicing".