In a message dated 97-05-22 09:18:10 EDT, you write:
 
<<
 Sue Hubbell's "Book of Bees" mentions this kind of "top" entrance. She is
 working, I believe, in the Ozarks. How far North does this type of thing
 make sense? I'm in NC close to the SC line.
  >>
Works well in CT  some bees propolize the hole down to about one bee size
I drill em the size of wine corks so I can stopper them as needed.