Is it drone brood getting kicked out? or adult drones? Another theory could be that SHBs got a chance to lay eggs in the drone brood. So the workers are getting on with dealing with the situation before it gets out of hand. I have seen that happen in the past, which is why I try to avoid large areas of drone comb in the brood.
PS @Brad13. Up this way, there’s lots in flower & coming into flower. Bloodwood trees are giving beautiful displays of flowers. The Buckinghamias all over the place a heavily in bud & flower. I’m sure it must be similar down there. cheers