I have a couple hundred hives that have last years queens in them and that I would like to re-queen. My method in the past would be to use queen excluders to divide the two brood bodies, come back in 4 or 5 days and look for the queen in the one that has the eggs. This year I'm thinking of rather than looking for the old queen, I will just put queen cells in the top brood box, thinking that she will hatch out and kill the old queen and become the new queen. Has anyone tried this method before with positive success? What are some of your methods, those with several hundred colonies please? For me this year, time is a factor. Thank you, and best of wishes.