A queenless hive must start queen cells within 6 days of the last egg laid by a killed or otherwise lost queen or the hive will be hopelessly queenless, right? If queen cells are started within 6 days, but then destroyed on the 7th day, they are now hopelessly queenless, right? If you wanted to be sure a hive would accept an introduced queen, would they almost always accept her if they were hopelessly queenless after the 7th day, but before they started having laying workers? What would be the best time window to destroy queen cells, and to introduce a new queen in this scenario?