I'm definetely not a dog expert...This is my first puppy in my adulthood and I'm taking her to a trainer because she has been growling. The trainer just told me yesterday that anxious dogs tend to get aggressive at night because they have to release their energy before bed. Young puppies will run around in circles but older dogs don't do that as much and may just tend to seem ornery. If you can, I would see if there are any dog trainers around you who could help you address his anxiety....IF that's what it is. Hope that helps.