I began 4 hives three weeks ago with 2 lb. packages of bees on drawn out comb in 8 or 9 of the 10 frame deep. I checked last friday and they had pretty much have brood in 3 or 4 of the frames in each hive with 1-2 filled with honey and 1 filled with pollen. Since they took off right away I assume this past sunday which was 3 weeks since I shook the bees in the frames the brood would begin hatching. The question is when should I add the next deep of undrawn frames?