US Patent 11980177 Differential pest sensor

A pest sensor and a detector for use in a pest sensing system are described. The pest sensor comprises a processor configured to: receive a first signal indicative of a first impedance across a first sensing circuit; receive a second signal indicative of a second impedance across a second sensing circuit; and in response to detecting that one of the first or second signals differs from the other by more than a predefined difference threshold, output an indication of pest activity.