We have a 1 year old siberian Husky who I've had since he was 12 weeks old. We have recently adopted a 6 month old husky. They get alone fine when they are outside. They play rough, run around and have no escalation. But once I bring them inside the older one will attack the younger one out of nowhere. I have removed. All toys, and treats in the room. Any thoughts on how we can correct this?