Cat got your tongue?
(Meaning: "Why aren't you talking? Your silence is suspicious.")
Look what the cat dragged in.
(Meaning: something that looks ragged or discheveled, much like a mouse that a cat has caught and partially eaten)
When the cat's away, the mice will play.
(Meaning: If no one is watching, people will misbehave.)
Let the cat out of the bag.
(Meaning: to tell a secret)
- For Teachers