At about 6 months of age Gage started showing signs of being protective of us and our home. Nothing aggressive just a hilarious howl followed by some barking and growling. I've never heard a boxer howl until I got him. Now that we have Teagan too, they notice every little change in the house, our yard, even our neighbors yard. Yesterday they were freaked out by the sears truck in the neighbors yard is was so funny. As soon as people approach usually Gage starts wagging his little nub but Teagan will have nothing to do with people on our property until we tell her it's ok. She's hilarious too she kicks up dirt and gravel with her back legs. My husband leaves around 4am to go to work and I feel very safe knowing any little sound they hear they'll surely let me know about it. They go crazy barking then come scratch on my door until I check it out and tell them it's ok. They wouldn't hurt a soul but they sure sound like they would! They're the best alarm system I've ever purchased. Also watched a special on 60 minutes about an expert robber who finally got caught. They were interviewing him asking ways to avoid being victim of a robbery and over alarms, dead bolts and all he said if he heard a dog bark he found another place to break into. Isn't that neat.