When my son was 10 years old, and I was away for the evening, someone with a gun attempted to enter our home. We had a Saint Bernard, and every time the person would begin to open our door, the Saint Bernard would lunge, and the person would close the door. My son, who had been sleeping downstairs, became aware of this. Stealthily, he crept up the stairs, one quiet step at a time. Finally he reached the top, slammed the door and turned the deadbolt lock.