Its implanted into the nutial ligament (yes, I murdered the spelling). It is VERY important to get it into that ligament. If it misses, the chip can migrate through the body. They have been found in hocks before, migrated from the neck. If you just have one or two I'd highly recommend talking to your vet, buying the chips yourself, then having the vet "install" them and test. Remember also that you are HIGHLY recommended to verify the chip's operation before AND after implanting, and that requires a reader.