An animal access system (1) comprises a lockable access door (11), an access door surround (29), and an implant adapted to be inserted through the outer tissue of an animal. The access door surround (29) is provided with an induction coil (30) operative to induce an electro-magnetic field at the access door (11). The induction coil (30) is controlled by control means (21) operative to generate a control signal to lock or unlock the access door (11) in response to a change in the induced electro-magnetic field generated as a result of the implant entering the induced electro-magnetic field.
