Apparatus for deterring squirrels and other unwanted intruders from tampering with a bird feeder of the type mounted onto a vertical pole includes a hollow, electrically insulating form having an upper portion and a lower portion defining a length, the form being physically configured to fit around at least a portion of the vertical pole. First and second electrically conductive, spaced-apart wires are coupled lengthwise along the form such that they do not touch one another. A high-voltage power source is provided having first and second terminals, each terminal being electrically connected to a respective one of the wires, such that a squirrel or other intruding animal will receive a non-lethal shock if and when the animal makes contact with both of the wires at the same time.