If it remains a real problem there are bark collars out there. Some are shock some are spray oriented. The shock ones are not at all cruel like they used to be. They react to the first bark by making a beeping sound. If he barks again it gives him a very light shock meant to be uncomfortable not painful. If he continues to bark it slowly increases the shock until it's strong enough to get his attention. I can attest to the effectiveness of the bark/shock collars. At first, I thought it was really cruel (this was not my dog... my roommate's), but they really aren't, as buc explains. The breed in my example is a mini-schnauzer & terrier mix, iirc... so, territorial. Our living arrangement wasn't as 'open' to passersby as yours, but there was plenty of foot traffic past our door. Charlie would get very territorial & start barking, and he barked a lot when his owner(s) was/were gone - even if I were still there. If I was home, I'd just have to semi-constantly be telling him to stop/interacting with him, or else he'd bark at the first noise from the hall. The bark collar was 100% effective in less than 3 weeks, and once it was successful, they didn't even have to use the collar on him anymore. It just modified his behavior - pretty amazing, as the target goal for such a product couldn't possibly be any greater than that. Look at it this way - if a bark collar doesn't modify Tyson's behavior, at least you know it'll be successful for as long as he has to wear it. I'm not sure if Charlie ever connected the collar with a negative connotation - he never fought wearing it. I don't think he realized anything more than, 'I'm not allowed/supposed to bark while I'm inside.' Highly recommended for your situation with Tyson! http://forum.brewerfan.net/images/smilies/smile.gif