A microchip is a permanent identifier, about the size of a grain of rice, placed under the skin usually between the shoulder blades. This has an individual number unique to your pet that can be scanned once found. Please note, microchips are not GPS devices; they will not help locate your pet if lost. Your information is kept securely at the associated microchip company. When scanned and called into the company, the number brings up you as their owner, with your phone number and hopefully, a joyful reunion!