Hi George,
 
I think your queen may well have squeezed through. I had one that did
that, she was a bit of a runt. She laid well though and no complaints on
that score. Nonetheless she was superseded after one year. At the time I
found brood in the middle of the first frames above the excluder as well
as below. I searched every frame above and below and just could not find
her. Then as I went to put back the queen excluder, there she was, and
as luck would have it she squeezed through the excluder before my very
eyes. So that was the end of that mystery.
 
I kept her out by keeping a super of sealed honey above the excluder,
and as I say the bees superseded her anyway later that year.
 
As regards why she would not kill the other queen. I think this idea that
the old queen is always killed is not as absolute as the books would
have it. I have seen 2 queens coexist in a 3 frame observation hive,
which you would think would be the last place one would expect to see 2
queens together - with so little space. One was the old marked queen and
the other was a new one. What's more I watched them approach one another
(thinking this was it now and the big fight was about to happen) only to
see them both tuck there abdomens into a cell and lay an egg, with their
heads almost touching. They had lived together for three weeks at that
point.
 
R.O.B. Manley has several stories to tell in his book 'Bee Keeping in
Britain', in one of his hives he observed the old and young queen,
usually on the same frame, at every inspection that Spring and Summer.
They had lived together through one winter already at that point, and he
reckoned tehy were together for over one year in total.
 
The hypotheses would seem to be that queens reared under a supersedure
impulse do not have the 'instinct' to fight it out. Perhaps at some
level they know their turn is coming, and that their purpose is not to
produce another colony only to continue that one.
 
Another reason is that it is very easy to damage some types of queen excluder,
and it doesn't take much of a knock t allow space for a queen to get through.
 
Then again, maybe they have read Plato's 'Republic' and heeded his advice. He
thought that a colony needed more than one 'king' bee, because one alone could
not hold the whole thing together. Too many and they would start to compete
for the sympathies of the hive and would then take off with part of the
colony, thus leading to disunity. Hence his 'Republic' was to have several
(but not too many) 'philosopher kings' to keep a healthy and stable society.
What's more he had no time at all for drones. He would have made a ruthless
beekeeper. Just thought I'd throw that one in.
 
Madeleine