What is a microchip? A microchip is a radio-frequency identification transponder that carries a unique identification number, and is roughly the size of a grain of rice. When the microchip is scanned by a vet or shelter, it transmits the ID number. There’s no battery, no power required, and no moving parts. The microchip is injected under the loose skin between your dog’s shoulder blades and can be done in your vet’s office. It’s no more invasive than a vaccination. So, that’s it?