I've "read" that they will often eat the discarded brood for protein purposes.
I'm not completely sure of that with honeybees being the ultimate vegetarians
. That said; The few dead bees left in front of my hives are usually gone by morning. I see yellowjackets fiesting on them regularly during the day.
I would think that if they do require some protein and do in fact eat their dead (or living for that matter) we wouldn't see so many being removed and discarded, after all, they're already inside, so why take them outside?
I'm just uncertain about it is all.
Here is an August post from Mr. Bray:
>Bees will consume stores during inclimate weather both to survive and to rear more brood, when the honey and pollen is gone they will cannablize the brood, eggs, larva, and any pupa still in the white. A hive can starve to death in less than a weak if the weather remains bad and the hive continues to rear brood.