The photos above show a gate in three positions--open, mid-position, and closed. The gate should be left in its open position during the nesting season, and otherwise closed to prevent squirrels from taking over the nest box.

An extendable painter's pole with an attached paint roller handle (minus the paint roller) is used to move the gate between positions. The tip of the paint roller's shaft is inserted into the PVC pipe to operate the gate.

This technique can be used for boxes that would otherwise require a ladder to reach.

Insure that the box is empty of inhabitants before preventing access.