My dogs don't do this, but I've always wondered about it. Why will some dogs jump up and snap at or bite you if startled from sleep? Is it bad temperament, or is like some people who will reflexively punch you in the face if you startle them awake? I have heard several stories about this type of thing. One was somebody who had a male doberman when she was a kid for several years, and then her dad went to pet the dog while he was laying down (like he had done lots of times) and the dog happened to be asleep and startled awake and bit the crap out of the dad, and the dad took him out back and put him down right then and there. Somebody else spoke about it being something that happens with some greyhounds, she has her own greyhound that will snap if startled awake. With rescued greyhounds I might understand that, because they weren't raised in a house, they were raised in a kennel where people aren't going to be petting them often or tripping over them, etc. so they wouldn't have been socialized to that sort of thing. I've always wondered if snapping/biting when startled awake was an uncommon behavior, if it means the dog is unsafe, and if there are ways to deal with it. Thoughts?