Abstract: A bird feeder with electronic squirrel deterrence that includes a bottom, a top, a swivelling hanger, a reservoir for storing bird feed and at least one feeding opening disposed in the reservoir. Feeding roosts having a perch are received in the feeding openings and inserts, having selectively sized beak openings and selectively sized feed baffles are received by the feeding roosts in order to accommodate birds of various species. In one embodiment, the bird feeder includes correction circuit for administering an electrostatic shock to a squirrel. The roost, the bottom, and the top include conductive surfaces which form an open circuit. The circuit is closed when an animal such as a squirrel makes contact with the conductive surfaces and one of the feeding roosts and delivers a mild electrical shock to the animal.

Abstract: A system for tracking articles or persons comprising a base unit for transmitting a series of ultrasonic signals and an alarm signal, a remote unit, removably attached to the article or person, for receiving the series of ultrasonic signals from the base unit and for transmitting an electromagnetic signal upon receipt of the ultrasonic signal from the base unit, and a monitoring unit for receiving the alarm signal.