It is only in very rare instances (such as those we have mentioned when speaking of the introduction of a stranger-queen) that the workers attack and kill royalty. Queens, on the other hand, are never known to use their stings against their subjects. They reserve them for combats with their equals, thus realising the salutary arrangement, which might have such practically important political consequences if adopted in human affairs, "Let those who make the quarrels be the only ones to fight." The queen, though developed more rapidly than the drones and the workers, enjoys a much longer life than her subjects. In some instances this period has been known to extend to five or even six years; but her fecundity is said to diminish after her second year, or, if it continues, she will in her old age lay a majority of drone eggs, to the serious weakening of the community. The skilled apiarian, therefore, takes care that every hive shall have a queen of an age when her fertility is greatest. The process of egg-laying begins from two to four days after the flight for mating, depending somewhat on the preparation of cells for that purpose. The queen, on finding comb adapted to her needs, thrusts her head into a cell, apparently to ascertain if it is empty, and of the right depth and size for one of the two different kinds of eggs--those for workers, and those to become drones. Satisfied on these points, she withdraws her head, and, curving herself downwards, inserts her abdomen, and giving the lower part of her body a half-turn towards the thorax, she expels an egg from her oviduct, and then retires in search of other cells in which to make similar deposits. She rarely, and only by mistake, lays more than one egg in a cell. If she falls into the error, the worker-bees immediately remove all but one. The examination of each cell by the queen to ascertain its fitness for the two kinds of eggs is an essential point; for, in the first place, the nature of drone-eggs is radically different from that of those which will produce workers; and the size of the cells in which the former are hatched is considerably greater than that in which the latter will be developed, nineteen ends of the larger covering a square inch of surface, while twenty-seven of the smaller will occupy the same space. It seems an indisputable fact that the queen has the power of laying which of the two kinds of eggs she pleases. The essential difference between the two seems to be, that those which will become drones are not fertilised by spermatozoa just previous to leaving the oviduct, while the worker-eggs are thus specially vivified, and the operation appears to be under volitional control.