There were several posts in recent times about queen piping.  I posted how I had heard the piping from a frame which did not contain the queen.
 
The other day I was catching queens and heard the piping noise from a frame that I had just removed.  I looked for the queen and could not find her.  I found her on the next frame and caught and caged her.
 
I picked up the first frame again and I heard the piping sound again.  I looked very carefully at the frame and then saw a worker, with pollen on her legs, flattening herself on the frame and emitting the piping noise.  I saw her do this flattening action and piping several times.
 
I remember a post where the queen was described as doing this flattening action and piping
 
Not being able to analyse the sound I am not sure if it is the same piping noise the queen makes but it is very similar.
 
Trevor Weatherhead
AUSTRALIA