GS response to darkness

Question
someone who used to own German Shepherds told me that the dogs go into a supersensitive alert mode in the dark and so whenever I leave the dogs alone in the house I should make sure that there is plenty of light, or  else they may not be getting sufficient rest.  Is there any basis of truth in this? Can you explain when this means?

Answer
I have never heard that.  The dog guide school certainly never said anything about leaving their Shepherd puppies some light at night.  Shepherds are slower to cycle down than Labs.  I see a lot of them in meetings, booth duty, etc. and given a chance the Labs will snooze.  Nothing that moves escapes the Shepherd.