Robin - yes, mostly drones - maybe 20% or so are worker size, (which could mean 'mini-drones', ex-drone-laying-queen colony - the frames from which I spread around the apiary a short while ago). I've got landing boards on roughly half my hives and, with the exception of guards that sometimes come out onto the boards to challenge intruders, the bees are either 'in' or 'out' - I've never seen them congregate on the board quite like this before - so I thought it was worth taking a picture.
This sight is occurring every afternoon, roughly between 3 and 4 p.m. They appear to be just 'hanging out', touching antennae and chatting away, otherwise not showing much in the way of activity. Unlike the busy in-bound and out-bound foragers which are skimming over their heads to and from the hive entrance, it's as if these guys are all on vacation ... very curious.
Mikey's post might offer a solution to 'why' this hive and not others ... the combs in this hive are not yet fully drawn out, so there's a 2-3" gap at the bottom of the frames - only inches away from the Landing Board - so maybe the drones don't make any distinction between that space, and the area just outside - which, during the afternoon, is being pleasantly warmed by the sun.
Well - it's a theory ...
LJ