Re: Question about Queens
Sometimes, if you manage carefully, you can manage to have a huge colony with two queens - mother and daughter. It has been reported in the literature.
But to answer your question more specifically, it is nature's way of perpetuating the species. Whether you accept evolution or the hand of a Creator, or combination thereof, for one of those mysterious reasons, it was decided that a second queen enables the colony to split, thus establishing two colonies (parent and child, if you will). Thus if something happens to one, the other might survive, ensuring perpetuation of the species. Not all of your eggs in one basket, as it were. If both survive, the following year they split again, thus four colonies.... in nature it is a matter of numbers.... So with honeybees, the more colonies there are, the greater the probability the species survives.
There was an article in our newspaper this past week about a faun that was found, in ill health, overloaded with ticks. I might have this backwards, (probably do!) but the article quoted an expert that 60% of the fauns die each year. Only 40% mature. So for the species to survive, you have to have a high birth rate. The hive swarming is the birth of a new hive.
Another factor would be space. A prolific queen can lay 1,000 to 2,000 eggs a day. A good queen could thus, in nature, fill up available space, lounge around for a while, then get to work again... There just would not be enough room, physically, in a natural hive (tree hollow, or wherever) to accomodate two normal laying queens.
"If all you have is a hammer, the whole world is a nail." - A.H. Maslow