How to Find Bugs: Warning Signs, Self-Check and When to Call a Professional

If you suspect someone is listening in, you want certainty. Yet the line between a justified concern and a false alarm is often just a gut feeling. This guide explains, calmly and factually, which signs matter, what you can check yourself, where phone apps and cheap detectors fall short, and what a professional bug sweep involves.

Warning signs of listening devices

No single sign proves surveillance. Pay attention when several come together:

• People know things they shouldn't – content of confidential conversations, negotiating positions, private plans.
• Changes in the room: moved furniture, new objects (chargers, power strips, smoke detectors, décor), fresh drill holes, loose socket or switch covers.
• Unusual access: tradespeople, cleaners or visitors you didn't arrange; signs someone entered while you were away.
• Vehicle anomalies: unknown components, cables or small boxes under the car, in wheel arches, at the OBD port or inside.
• Conflict situations: separations, inheritance disputes, shareholder conflicts, negotiations or competitive pressure raise the risk.

Clicks on the phone or a warm battery are commonly cited but usually have harmless causes. The strongest indicator is information that demonstrably leaks.

Finding bugs in your apartment: what you can check

1. Take inventory: what is new, what was a gift, what isn't yours? Focus on items with permanent power (adapters, USB chargers, power strips, clocks, lamps).
2. Look at power points: sockets, switches, ceiling lights – from the outside only, without opening anything.
3. Check sightlines: where could a hidden camera see your bed, desk, screen or keyboard? Tiny holes or glints in smoke detectors, frames or shelves may indicate a lens.
4. Check your network: your router's device list shows what is connected. Unknown entries deserve a closer look.

Don't discuss your suspicion in the affected room or on a possibly affected phone.

Finding trackers in your car

In vehicles the concern is often GPS or GSM trackers rather than microphones. Use a torch to check wheel arches, the underside of bumpers, under the seats, boot linings and the OBD port. Don't remove panels or tamper with the wiring – you may cause damage and destroy evidence.

Finding bugs with your phone: why apps and cheap detectors mislead

"Bug detector" apps mostly use the phone's magnetometer, which reacts to metal and magnetic fields – screws, cables, speakers – not to radio signals. Lens-finder apps may spot an exposed lens but fail with well-concealed devices.

Simple RF detectors have limits too:

• Wi-Fi, Bluetooth, phones and smart-home devices transmit constantly, causing false alarms.
• Some devices transmit only intermittently, via the mobile network, or not at all, storing recordings locally. A basic detector often misses them.
• "No signal" therefore does not mean "all clear".

The real risk is false reassurance.

When you need a professional

When information demonstrably leaks, when a concrete suspicion coincides with a conflict, when you've found something suspicious, or before an important meeting, negotiation or board session.

What a professional sweep includes

A proper bug sweep (TSCM) combines several methods, because no single tool finds everything:

• Radio monitoring: spectrum analysis to separate active transmitters from legitimate signals.
• Non-linear junction detection (NLJD): finds electronic components even when switched off or not transmitting.
• Optical and thermal inspection: for hidden cameras and heat sources in walls, furniture and objects.
• Line checks: 230 V mains, Ethernet and telephone lines.
• Vehicle checks: GPS and GSM trackers.
• Pre-meeting sweep of the meeting room right before an important appointment.

You receive a written inspection report. Cost: €30–40 per m² plus VAT, including the report.

If you find a device

Under German law, planting a listening device can be a criminal offence (§ 201 StGB, violation of the confidentiality of the spoken word; for images § 201a, for data §§ 202 ff. StGB). So:

• Don't destroy the device, and avoid touching it.
• Document location and condition with photos.
• Consider reporting it to the police and taking legal advice.

This is not legal advice. Identifying who is behind it is investigative work – for that we cooperate with our partner, the Hamburg detective agency AC Detective.

Security as a whole

At DV Company, bug sweeping is part of a security concept built around close protection. Our founder Vadim Dischewski has worked in personal protection since 2008. For companies we also offer a polygraph as a voluntary, supplementary tool in internal investigations. See also bodyguard costs.

Confidential first consultation

Book a free, confidential first consultation via our enquiry form. Please don't contact us from the affected room or the possibly affected phone.