A microchip is a tiny electronic device, about the size and shape of a grain of rice. It is implanted beneath a pet's skin between the shoulder blades, and stays there for the pet's entire life. This procedure is as easy and as painless as a vaccination.
Each microchip has a unique number. This number, along with information about the owner and pet, are added to a national pet registry. Most veterinarians and animal shelters have electronic scanners for detecting and reading these implanted microchips. If a lost pet is found, and the microchip is scanned, the registry is called and the owner is contacted.