Cause when you pull the trigger on a gun, it goes bang and shoots a bullet out of the barrel, and if properly aimed it can incapacitate the bad guy leaving him to either die as he ponders whether it really was worth his life to burgarlize people, or it can leave him severely wounded while the police show up and then he can have 15 years in jail to think about it.
 That 12 gauge you mentioned -- do you take it to the grocery store when you pick up milk?

So exactly how does this dog thing work?
 They bark a lot, and scare the crap out of people who might otherwise think about breaking into your house. Then they decide to move on to another, easier target.

--Dan.