About October 20th I looked into the wild bee nest and I had a surprise. It was empty of bees! The combs were hanging clearly with no bees in attendance. So I went back two days later to get a picture and this is what I found.
There are still plenty of bees in the nest and they still appeared to be working actively, though none were flying in and out.
I looked in again yesterday (October 26th) and it looked deserted again! Do the bees have a hiding place further into the hole, behind the combs? Do they huddle together for warmth? I don't know the answers so I'll keep watching.
For the earlier parts of the story see Bees! and More bees!