A pair of Jehovah's Witnesses knocked on the front door of a home. They heard a faint, high pitched, "Come In" from within the house. With some reservations, they turned the doorknob and entered the living room.

Immediately, a huge, snarling Doberman cornered them. Plastered against the wall, they cried out for help, only to again hear the same little voice say "Come In".

Looking around the room, they identified the sound as coming from a cage, within which was a huge parrot!

In fear and frustration, one of the Jehovah's Witnesses shouted at the parrot "Is that all you can say?"
The parrot cocked his head to the side, looking at them very carefully. Then it said, "Sic 'em! Rover"

Squawk!