I have noticed my dog will wake up out of a deep sleep and stand up in full alert. There were times he used to growl. I just thought he was imagining things. Lately he is in a deep sleep and stands up. I watch him following something he sees. He is just keeping a close eye on it. He then lays down and goes right back to sleep. One time when he sensed something and was peaceful I too felt a sense of peace wash over me. Indescribable. I pay attention to what he is sensing. This is wise advice DD and more to it than we may know.