I never said anything about them being up in my face. I can't imagine they would ever do that if they were there to check out my 4 plants. They typically treat things like this as a "casual inquiry" initially, I prefer to remain courteous (but not "friendly"), look them in the eye, and have the right answers to their questions.
Become quiet or shifty, or have the wrong answers, and things can start to get a little more "in your face".
As I said, I remain sceptical about cops - but this is Canada after all. LEOs (in my home town, anyway) generally have a pretty casual initial approach. Why would I immediately go on the defensive and clam up when I am not breaking the law? Terrible idea.