That's a good question -- thanks for asking it and to everyone for your helpful replies.
I do have a question about this though:
I do have a question about this though:
My puppies are only 4 months old, but they have started growling (and sometimes barking until I thank them and tell them they can stop) when someone they don't know comes onto our property. Are you saying that's not normal? They are very well socialized and when they take their cue from me that a visitor is a friend not foe, they become friendly and greet them with tail wags (for example, we had a crew of about 10 landscaping workers... all men... that they had never seen before... once they saw me greet and talk to them, they bounced up to them wagging their tails).