This invention relates to a device and method for containing animals, and more particularly, but not exclusively, to a device and method for containing domesticated animals within a set perimeter (19). According to a first aspect of the invention there is provided an animal containment device comprising at least one magnet (12) for setting a perimeter (19)； and a transceiver securable to an animal, the transceiver configured to detect a magnetic field emitted from the magnet, the transceiver further being provided with alerting means, wherein the alerting means is configured to emit a signal when the transceiver detects the magnetic field.
