1. An animal indicator apparatus operable to be worn by an animal, the apparatus comprising: a location determining component operable to determine a current geographic location of the apparatus; a memory operable to store cartographic data including data representative of a location of at least one boundary; an indicator including a light-emitting device; and a processor coupled with the location determining component, the memory, and the indicator, the processor operable to activate the indicator when the current geographic location of the apparatus is near the location of a boundary; wherein the processor varies an intensity or blinking rate of the light-emitting device as a function of a distance between the current geographic location of the apparatus and the location of the boundary.