The microchip is only activated when a scanner is passed over it, otherwise the chip is completely inert. When a scanner passes, the chip emits electromagnetic waves, causing it to transmit a unique radio signal back to the scanner.  It’s very quick, and completely harmless to your pet. If your pet is lost, the person scanning the chip can read your pet’s unique identity code and use this to trace their owner (you) – by referring to the database.