dFortune, guess again. No backfilling here. The queen always has empty frames in front of her.
:thumbsup: That's it. The speed the queen is laying eggs is more or less fixed. If you provide too many brood combs the queen needs longer to move on her "laying path" from one end to the other. Longer distance, same laying speed. This results in free cells by emerging brood that do not immediately receives eggs after they are freed. Free cells = bees putting pollen and nectar into it. When the queen comes back to that cells from her journey through the hive, she founds no or little free cells to lay eggs into. You end up with pollen and nectar and brood clogged combs.
The masterhood of beekeeping is to phase/synchronize the distance and speed of the laying pattern of the queen. By adjusting the size of the broodnest to the performance of a queen.
You end up with a well-tuned broodnest. The queen returns exactly to the first cell she layed eggs into at the time the brood emerges. Since the brood emerges at the speed the queen is laying eggs, the queen has the chance to fill all emtpy cells with eggs. And not being outpaced by the workers.
It is quite simple. After wintering, very very early, remove all combs out of the broodnest that are not covered by the cluster. This way you adjust the broodnest to the performance of the queen, because the overwintered cluster pretty much shows the capacity of that queen. (If all else is ruled out, like varroa, starvation and so.) Do not add more combs to the broodnest until well into the season. I know it is hard to resist seeing all those bees crowding. Instead add supers! Have more supers on than bees are in that hive. Bees will fill those supers and even build lots of comb in no time this way.
That is pretty much it. The other approach would be providing lots and lots of brood boxes, so somewhere in the brood boxes is a free cell for the queen to lay an egg into. But I found this a waste of ressources and additionally when the broodnest is more compact and tight, the warmer it is. You also end up with more honey in the supers instead in the brood combs. A nice side effect is, that you can make some honey even with smaller colonies.
And you have less swarming. Which is because you have much less combs to go through breaking cells. I keep bees successfully on 8-10 deep brood combs. Much less work, less ressources, maximized honey per box ratio.
And this way you have no problems at all bees going through the excluder and drawing lots and lots of combs. Just do not add more combs to the broodnest. The broodnest doesn't need so many cells for the brood. In fact during the first month of spring only one fixed number of brood cells is needed. No need to increase the number of brood combs. That only triggers nectar and pollen storage in the brood boxes.