In Australia, this is often referred to as "Rothenbuhler syndrome".  It is
said that these are resistant but I am not sure what to.  I am unaware of any
tests that have been carried out.
 
I often wonder if this phenomen was associated with Rohenbuhler's AFB
resistant bees.  Does anyone know?
 
I have had hives do this but only one or two in an apiary.  I have a photo
somewhere of bees washboarding up the front of a hive.
 
Trevor Weatherhead
AUSTRALIA