As paredes tem ouvidos. (Portuguese: The walls have ears.)
topic: Wall, Walls Have Ears, Ears, Portuguese

That field hath eyen, and the wood hath ears.
source: Geoffrey Chaucer, Charles Cowden Clarke (1835). “The Riches of Chaucer: In which His Impurities Have Been Expunged, His Spelling Modernised, His Rhythm Accentuated and His Obsolete Terms Explained; Also Have Been Added a Few Explanatory Notes and a New Memoir of the Poet”, p.103
topic: Walls Have Ears, Woods, Fields, Medieval War
What goes around, comes around.
source: Willie Nelson, Turk Pipkin (2006). “The Tao of Willie: A Guide to the Happiness in Your Heart”, p.33, Penguin
topic: Karma, Respect, Revenge, Married With Children, Hurting Someone
The walls have ears, better think before you throw that shoe.
topic: Relationship, Wall, Thinking, Walls Have Ears
topic: Song, Wall, Lying, Walls Have Ears
topic: Wall, Ordinary, Ears, Walls Have Ears
The walls have ears, ears that hear each little sound you make every time you stamp, throw a lamp.
topic: Wall, Advice, Sound, Walls Have Ears