Hi George,

> I have always thought of a double screen as one of the most useful tools
in
> an apiary, but none of the major bee supply houses sold them.

Betterbee has had them for as long as I can remember (which sometimes
isn't even yesterday ;-).

> I have kept queen banks OVER a double screen for years with an upper
entrance
> to that body.
So where do the attendants for the caged queens come from?  Above a queen
excluder the attendants come through the excluder while the aueen of the
colony stays below.  With a double screen (correctly called a Snelgrove
board)
nothing came get through.  I'm confused.

Cheers,
Aaron