Queen and Laying Workers?

[heaflaw]

Last week when I went to rob one of my hives, I found that the 2 honey supers were about half full of drone brood and had lots of drones.  I assumed something had happened to the queen and I had laying workers.  I took what honey I could and combined the supers into one.  I could tell there weren't many bees below the excluder, but I didn't go into the deeps.  Today was the first chance I had to get back to it.  I found sealed drone brood above, but no larva.  To my surprise, I found that below the excluder was a queen with eggs, larva and a little capped brood filling about half of two frames.   There are probably 15,000 bees in the hive and about a fourth of them are drones.  I know the hive swarmed in late April.  It had come through winter very strong and I was too late with any swarm prevention.

What has been going on?  Why would there be laying workers and a queen?

[Robo]

If you left brood above the excluder when you put it on, there is a good chance they raised/or attempted to raise a queen.   If there was no top entrance or she didn't mate, you may have a drone layer above the excluder.

[Michael Bush]

http://www.bushfarms.com/beeslayingworkers.htm

[heaflaw]

As I understand your answers & what else I have read, the cause of laying workers was that for some reason the queen was not laying for several weeks and now that she has started laying, the laying workers have stopped and my problem is solved.  It is a week hive, but should recover enough to get through winter.
 
One more question: are the drones from laying workers fertile to mate with queens?