Hi all , our Shihtzu (1.5 yrs old) is becoming quite a little barker . When were in and there's a knock at the door he goes off alarming ,he bolts for the door barking his head off , if the kids are playing upstairs and make bang on the ceiling he barks thinking there is someone at the door , if i tap my cup on the glass table he barks thinking someones at the door ,or if someone walks past the house he barks. Now my problem is ,is that i dont want to keep saying " nobodys there" or "stop" " no " etc as i do think that sometimes when i don't hear the door he doe's bark to tell me so if i constantly say stop then he will do . I dont want this because there was a time recently when he did bark and bark and kept on barking until he woke us up in the early hours to tell us he could smell fire and what i believe potentially saved our lives (good boy ) ! I think he is quite a protective dog in this sense but how do i cut out the unnessecary barking ?( i always check out all of his barking). When he thinks he's heard the door knock i always take him to show him that no one is there ,but when someone is there i keep him in the living room because im frightened that if i answer the door he'd just bolt for it . If the person comes in he's all over them like a rash as if to say " look at ME play with ME dont bother with them its ME youv'e come to see " . So i think my question is ,is he just protective ? is he protecting his enviroment ?
Btw we have gone out the house waited 5 minutes then knocked on the door ..not a peep out of him !
p.s weve had him from 12 weeks old and were the only owners if this helps?

ps when i say he goes off alarming hes not distressed ,frightened or in fear of the knocks i just ment it as a figure of speech ,more like bull in a china shop alarming :P