Hello we adopted 2 terrier-mixes from the shelter last year. They were very scared when we got them and it took a long time to socialize them to other human beings as well as other dogs - still a work in progress. They are boys - one being the alpha, the other the submissive. I have a problem with the submissive one occasionally biting strangers - usually men - on the ankle. The most recent example was over the weekend - we had a holiday party and one of our guests brought his large dog without asking first (not a smart move to begin with!). My dog freaked, barked and basically said to that dog "get out of here". The guest put his dog in the car and rejoined the party but for the rest of the party my dog treated him as a threat and eventually bit his ankle. I was horribly embarassed. What behavior is he exhibiting? How do I prevent him from biting people? I realize that he was just protecting his territory but this is not any way to behave in general. I would appreciate your help.