What does "when pigs fly" mean?
Greetings to you, Svetlana Petrovna.
Since pigs can’t fly, this phrase is used to figuratively say that something is never going to happen. This is a form of sarcastic remark conveying the absurdity of someone’s idea or thought. It can be used in the simplest things in our daily lives, just like when a lazy person claims to have cleaned his/her room.
His/her mother could say, “Oh really when pigs fly! I better not see any trash in your room if that’s true.”