I have noticed that my dog has 3 different kinds of barking behaviour. One is where she just barks by the window or the door, two is where she barks and runs from one side of the house to another and the fur on her neck stands up, the last one is where she is running from each room and jumping up at windows and doors and the fur on the whole of her back is up. What does all this mean, I am not sure if I should comfort her or just ignore her, is she protecting or is she scared? The barking by the way could be at a truck going by, thunder, people walking by or she hears other dogs barking.