Ever since a strange man walked into my apartment at 5 am one morning, Joey seems to be more sensitive about people in the dark. I'm home with my parents recouping from my surgery. Joey and I were up late last night watching tv. My dad started walking down the stairs (which were in the dark) and Joey stood up and started growling. Once my dad talked to him and he seemed to recognize my dad he was fine and even acted kind of apologetic. He sat next to my dad and leaned up against him. (he's really fond of my dad for some reason) He's done this a couple times now with my dad and my brother. Once he figures out who they are he's fine. He absolutely loves strangers when we go for walks and such in the light. Is this an okay behavior or should I be worried?