Just wonder if any of your here have seen workers being reared in drone
cells.  I do not know if
1). this occurs under natural conditions or not and
2). whether it is seasonal.

however I observed both A. mellifera and A. cerana queens laying fertilized
eggs in drone cells, late in the fall (Sept-Oct), when FORCED to lay eggs.
I.e. the queen was caged in a frame holder (a whole frame can fit with queen
excluders on both sides so workers can roam but the queen is imprisoned. she
has no choice but to lay on the frame).

Strangely workers rear these workers "to term" they emerge as normal workers.
I guess it is not so strange since drones can also be reared in worker sized
cells (when the queen is gone and workers start laying).

My impression is that the queen somehow refuses to lay unfertilized (drone)
eggs in drone cells when it is late in the season.  but I am pretty sure she
does so in summer.  Evidence for queen intelligence ? :) :)

Zachary Huang
http://www.cyberbee.net