Skunk track

I woke up to the sound of a loud thud.  I waited for a moment to see if it was just a sound I had dreamed.  No - heard another loud creak.  There was a light behind the window shades.   Must be something set off the motion detector lights on the out buildings.   2 a.m.  Looked to see if Blitzen was alarmed.  She had settled down next to me when I'd gone to bed but now she was nowhere on the blankets.    Heard another low groan.  I wouldn't be able to sleep until I'd checked out the house.  Slipped on some clothes, grabbed my phone and a weapon of choice, then started through the dark house.  Nothing seemed amiss.  Went on checking doors, looking in rooms,  and peering past window shades.  Nothing.  When I got to the foyer Whip was fast asleep.  From the foyer I could see no lights on Mjolnir nor Sleipnir.   I began to reevaluate my facts.   The night sky had begun overcast but had cleared.  It was the full moon shining off the new snow that was causing the backlighting on the shades.  The outside thermometer read 5 degrees.  Temps had been 50+ just two days ago.  All of those loud noises were  the house and deck adjusting to these colder temps.  I turned around and there were both cats watching me, tails held high, curious about what I was up to this time of night.    I padded back to my bedroom and crawled into bed.  Blitz curled up beside me and, despite the house's groans, both of us soon were asleep again.