This one is Rocky, my first line of security. He's the best alarm system ever devised. A squirrel cannot cross the back deck without him knowing about it. And letting US know about it. His utility won't stop at just detection, either. I've seen how he regards strangers, and I see intruders as a way of decreasing dogfood expenditures. He's no 130-pound Rottweiler, but he's no pushover either. What he lacks in size will be made up for with pure, unadulterated attitude.
I think I caught him here just as he was about to sneeze.
I posted about some issues with him a couple of years ago. I am happy to report that he's become every bit as much my dog as any of the others I've ever had. He came from an abusive environment, but it didn't spoil his sweet natured-ness. Since that time, there's been a whole lot of gentle talk, physical contact, and general positive attention given and that's what it took to gain his trust. He's curled up snoozing on the carpet right next to me right now. He has become a truly great dog!
Someone referred to his breed as the "Great White American Landshark." Not too far from the truth, but if you can gain one of these little carpetmonsters' affection and loyalty, no one will be helping their self to your stuff.