From Creatures Wikia
In C3/DS, each species of creature has what it considers its home. The Norns call the Norn Terrarium and Norn Meso their homes, while the Grendels and Ettins have similar feelings for the Jungle and Desert Terrariums respectively. A creature will often return to its home to lay eggs. The home of a species has its own CA that creatures can navigate to when they're feeling homesick.
The item that emits this CA is also called "norn home"/"grendel home"/"ettin home" in the classification system.