A pet tag with location and alarm functions includes a cover; a bottom shell; and a circuit board, wherein two convex poles are symmetrically disposed on the bottom shell, and a piece having a threading hole protrudes outwards from an edge of the bottom shell, wherein the circuit board is equipped with an electric horn sound-generating device, a power supply, and a signal transceiving device, wherein two positioning holes corresponding to locations of the convex poles are disposed on the circuit board, wherein the circuit board is installed in the bottom shell through matching of the positioning holes and the convex poles, and wherein the cover covers the bottom shell to accommodate the circuit board therein.

One embodiment provides a mapping device including a memory configured to store instructions. A processor is configured to execute the instructions to: receive geolocation information for the mapping device from a global positioning system (GPS) device; receive unique identification information; transmit the geolocation information and the unique identification information through a network; and cause an update to prior geolocation information that corresponds to an address in a mapping database.