Yes, they are too smart at times, for sure. It is amazing how they watch and learn your subtle day-to-day patterns of behavior around the house and yard. They know when I'm about to go out, almost as soon as I myself actually decide to go out.
And, when they hear that Gibson dual exhaust fire up when I start the truck remotely (parked 75 ft from the house), they go nuts, expecting me to take them out in the truck for a ride (which I usually do).
I have "Dog on Premise" signs on both ends on my semi-circular driveway, letting folks know these dogs exist, and not many folks enter the driveway these days, unless they have a specific purpose. The UPS guy pulls into the driveway, and if he sees the dogs, he sits in the truck and honks the horn, until I come out and round them up.
We have bears in our neighborhood, and a few years ago, they both stood between a bear and my wife in the driveway, barking and snarling. Of course, the bear could have torn them both apart if it really wanted to, but it chose instead to go back down the driveway and into the street.