Among the embodiments of the present invention is a system including a
pest control device and a magnetic field source external to the pest
control device. The pest control device has a bait operable to be
consumed or displaced by one or more species of pest, a pest sensing
circuit, and a monitoring circuit coupled to the pest sensing circuit.
The monitoring circuit includes a device responsive to a magnetic field
provided by the magnetic field source to output status information about
the pest sensing circuit.