(n.) A miniature electronic device that records sounds and transmits the playback to a remote receiver. Usually placed in internal settings, it's installed with regard toward optimal concealment and acoustic clarity. (There have been many new modifications to the genre of "bugs" from environment adaptability to signal transmission type. Due to the 4th Amendment, all forms of U.S. law enforcement require court permission along with strict rules in the use of these devices.)
Spetsnaz agents used a bug to capture enemy conversations in order to learn the whereabouts of POW camps and artillery encampments in the Soviet-Afghanistan War.