I have two dogs. the cool thing about dogs is they are very protective of their environment and owners.
That's right!  It seems no matter which breed and temperament, they all become "man's best friend."  I have a pug myself.
I have a Rat Terrier and a rescued French Bulldog both are good watch dogs and both are female.
I've heard of a Rat Terrier!  Is it good for keeping the house free of rodents, like a cat is?
Yes the rat terrier will even chase frogs off the porch. The rat terrier is very good for herding livestock in small numbers as well.
I think I might try to get one if it's as good a compainion as it is a pest controller