Walls have ears, '낮말은 새가 듣고 밤말은 쥐가 듣는다.'

There is a Korean proverb called "낮말은 새가 듣고 밤말은 쥐가 듣는다." 낮말 means "talking in the afternoon". 밤말 means "talking in the evening". 새 means "bird" and 쥐 means "rat". 듣다 means "hear". When we have a conversation in the afternoon, birds can hear what we say. In the evening, rats can hear what we say. This proverb teaches us 2 lessons. First, we have to be careful while talking even though nobody seems to be there. Second, any secret will leak out someday.