We bought an anti-bark device at D&B Supply for $50 or $70. Looks like a birdhouse. We hang it in a tree by the fence. No sure it works, but the barking may have decreased. There were some plans in Popular Mechanics a few months for a megaphone amplifier. I thought it would be worth trying to hook that into the anti-bark device. Give the critter a real blast of ultrasonic noise. No electronic experience, but thought it would be worth a try.dvc