Types of Bugs

A "Bug" is a device that is placed in an area, which then intercepts communications and transmits or conducts them out of that area to a listening post. The eavesdropper can be just a few feet away from the victim, hundreds of feet, or even miles away depending on the kind of bug used.

There are five primary categories of "Bugs": (Acoustic, Ultrasonic, RF, Optical, and Hybrid).

An Acoustic Bug is the placing of a water glass, stethoscope, or rubber tube into an area and directly intercepting the communication with the naked ear (without the use of electronics). This also applies to sections of an area where sound is leaking though soft spots around windows, structural defects, ventilation structures, poorly installed power outlets, and so on.

An Ultrasonic or VLF Bug is a technique use to convert the sound into an audio signal above the range of human hearing; the ultrasonic signal is then intercepted nearby and converted back to audio. In this case audio pressure waves are used instead of creating a radio signal.

An RF (or Radio Frequency) Bug is the most well known type of bugging device. A radio transmitter is placed in an area or in a device. This is your classic martini olive bug and "spy shop" store device. These are extremely easy to detect, cheap, disposable, but difficult to trace back to the person who actually planted it. A properly equipped TSCM specialist can actually detect this kind of device at a significant distance, but it does require some time to properly accomplish this task. Keep in mind that any legitimate bug sweep takes hours, or even days, but not minutes).

An Optical Bug is a bugging device that converts sound (or data) into an optical pulse or beam of light. It is rarely used, expensive, but easy to detect. A good example of this would be active or passive laser listening device.

Any of the above techniques and devices can be combined to make a Hybrid eavesdropping device.