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Listening Devices: What They Look Like & How to Detect Them

Keep reading to learn what a bugging device looks like, where they are commonly found in a home, and how to block out listening devices.

What Does a Listening Bug Look Like?

Listening bugs are always very small because they’re designed to be hidden and unnoticeable. Every listening device will appear slightly different, but they’ll usually look like the following: 

  • Very small and round, usually no more than 0.5 inches (1cm)
  • Black or silver plated, with a hole in the center
  • Similar to a small microchip
  • Like a small round coin
Small microphone of the overhearing device holding by a woman

Most devices are connected to a power supply and hidden within electrical devices, but some inexpensive bugs are battery-operated or rechargeable, so won’t always have wires. These might be used in holiday rentals where they can be recharged between guests.

How Does a Listening Bug Work?

A listening bug works by recording sound, usually within a 300-900 foot range, and transmitting it to a computer in another location. As the name suggests, they are small microphones that pick up sounds with clarity.

Two types of listening devices are used.

Wireless/Battery-Operated BugWired Bug
Inexpensive. Usually lasts a week, but may last up to several months.Expensive and custom-made.Works indefinitely, assuming the power supply isn’t disrupted.

Where are Listening Devices Usually Placed?

Common places to find listening devices include:

  • Phone chargers
  • USB chargers
  • Smoke alarms, especially those in the center of a room
  • Wall and ceiling lights or table lamps
  • Sockets
  • Cable boxes
  • Light switch plates
  • Wall or mantel clocks
  • Wi-Fi routers
  • Extension leads

Because they give off a high-pitch frequency and often require power, listening devices are usually found inside domestic electrical products and appliances

  • Under the hood
  • In the trunk
  • Under or around the edge of seats
  • On the underside of the dash (these usually lift off easily)
  • Behind the bumpers
  • On the undercarriage (use a mirror to check)
  • Inside the wheel wells

How Can You Tell if There is a Listening Device in Your Home?

Telltale signs of a listening device in the home include buzzing or ringing sounds, unusual placement of moveable objects, and damage done to electrical devices and sockets. If the device is hardwired, wires might be partially visible.

Here are the three best ways to detect a listening bug.

1. Look in Common Places

Most bugs need a power source to reliably operate long-term, so they’ll be hidden in your electrics (like sockets or light switches) or within an electrical product (like lamps and extension leads). Do an in-depth scan of your home, taking caution when inspecting electrical items. Seek help from a qualified electrician, if needed.

To temporarily disable the suspected bug, turn off your mains electrics to give you privacy while you search. Remember, the device may have a failsafe battery that operates for a period after losing power. So, just because your mains electrics are switched off, it doesn’t mean the bug is completely out of action.

Don’t assume there isn’t a hidden bug in your home just because you’ve checked all the common areas. They are designed to be covert, so a bug can be hidden anywhere. After searching, it’s best to check again (using a radiofrequency scanner or a smartphone app) to be certain.

2. Use a Radiofrequency Scanner

If you’ve found something that looks like a bug, or you want to search for a listening device covertly, you can purchase a radiofrequency scanner. These pick up anything broadcasting a radio signal, including bugging devices.

Other broadcasting devices include routers, smartphones, telephones, TVs, satellites, garage door openers, virtual assistants (like Alexa or Google Home), and any other Wi-Fi product. Anything transmitting a signal should be checked to ensure there isn’t a hidden listening device inside.

Be wary that some bugs are so advanced they are designed to evade even the most complex scanners. So, you should still check visually for bugs after scanning everything in your home.

Credit: Spy Geeks

3. Download a Smartphone App

If you have no reason to suspect there’s a listening device in your home or holiday rental, but want to do a quick check, smartphone apps offer the quickest, easiest solution to scan for hidden listening bugs. When using these apps, you won’t need to dismantle any electrical items or invest in special equipment.

How to Block Out Listening Devices

Should a device be uncovered, don’t touch or disable it. This will alert the spy and potentially prevent fingerprint verification. Instead, leave the premises immediately and find a safe location to notify the authorities.

If leaving the premises isn’t possible (for example, if the suspected device is in a moving car), there are a few ways to successfully block out the device. 

  • Distort the sound that reaches the device by talking quietly or speaking only when there is loud ambient noise
  • Transmit another sound to mask the sound, like white noise, blaring music, or a hoover
  • Block the sound completely using an audio jammer

Using an audio jammer is the best way to block out listening devices. Turn on the audio jammer when having a concealed conversation or keep it running continuously. They are also useful for preventing a vehicle outside the home from listening to conversations inside or on the property.


Remember, the most important things to bear in mind when looking for hidden listening bugs are:

  • Listening devices can be very small
  • Bugs can be wired or wireless
  • Bugs are usually found in electrical products and casings, or in cars
  • Even a very small device can hear sounds throughout the house
  • Use caution when searching for listening bugs to avoid detection
  • Use an audio jammer to block a bug from listening
  • Don’t touch listening bugs under any circumstances to preserve fingerprints and prevent alerting the spy