A vibratory detector for detecting a vibratory signal from one or more feeders. A processor is in communication with the vibratory detector and configured for determining from at least one characteristic of the vibratory signal a possible action event, and for determining from a pattern of possible action events a likely action event. A warning device is in communication with the processor for providing an output in response to the likely action event. In an embodiment, the at least one characteristic of the vibratory signal can comprise the frequency or magnitude of the vibratory signal.