Sleeping bees

I knew honey bees didn't hibernate but went into a torpid state where the workers slowly moved around the queen keeping her warm and taking it in turns to be on the outside of the cluster.
Because of this and the 'busy bee' ethic bees are supposed to have,  I sort of assumed they didn't sleep either.
I read somewhere that bees rest and a video showing the difference in activity rates during the day and night is here.

However it seems they do sleep after all and this was first suggested by Jurgen Taulz in his 2007 book 'Buzz about the bees' [awful title].
His work has been taken on and a recent article about it is here.