I have a very energetic pup that uses his mouth a lot. He is a sweet and very good-natured pup, just very enthusiastic, rambunctious and playful. He does know "settle" and does it beautifully (for a minute or two.)

You've probably all seen a dog move their hind leg in a scratching motion when you scratch their neck or ears. You're probably familiar with the other way a dog deals with an itch: by kind of nibbling at the itch with their incisors.

When I stroke certain parts of my dog's body during "calm time", sometimes he will "nibble" on my arm. He doesn't try to get away, and appears to be enjoying the physical contact, but my trainer said this is an aggressive attempt to control me, and should be strongly discouraged.

I did have a dog that would nibble my bottom, which I agree was a herding behavior. But this is on my arm and only occasionally. It seems like he's behaving as when he's biting his own itches.

Is my trainer correct? Should I immediately cease giving my dog attention when this happens? Any insights would be appreciated.