Dog digging floor in the middle of the night

Question
I have a 12 year old female black lab.  Despite her age she remains very active and healthy.  I generally have a good understanding of her behavior but there is one behavior that has left me stumped.  Ebony sleeps on the couch in the computer room, quite comfortably.  She enjoys being put to bed in there and will not bark until it is time to wake up the morning.  However, every night in the middle of the night I wake up to hear her digging into the hardwood floors. I believe I have found the spot where she digs although there are no scratch marks.  After digging for a few minutes I hear her lay back down and go to sleep.  She does not dig at any other time even when she's in the backyard.  I am not concerned by this behavior because, as I mentioned, she is a happy healthy dog. I am simply curious as to this repetitive behavior.

Answer
You may have little "guests"!  NOT uncommon, even I have had my share!

There's something about that spot that's quite attractive to Ebony; she returns to it habitually (if it is, indeed, the same spot.)  I have no idea which floor this is on (main floor or upper floor) but many little "guests" are nocturnal and, believe me, you may not even know they're THERE (NO signs at all!) except for your dog.  Since your dog is not waking you, and she's not obsessing about this, it's not really a problem but if you DO have little "guests" you may want to evict them.  Unfortunately, pest control services use poison that can also kill your dog and little "guests" can die in your walls (not to mention the dreadful death they suffer) or go out and be consumed by other animals who themselves die as a result of the poison.  If you have a crawl space, or basement, or hung ceiling, any space where "guests" can travel freely (or even set up shop), you might want to have these investigated for signs of squatters.  At least you'll know what your dog is trying to tell you and can then make a decision regarding how best to deal with the situation.