Here is a hive i have which is typical of the dead bees during "No Fly Days" in all it seems consistant around my 18 hives that i have a cup full of dead bees on the bottom boards and in front, so in all about 300-400 dead bees. I remember this same "look" this time last year so i am not worried.
What i did notice is the hives that had the Zia Queens, Bobby Oakes Queens, and Mike Carney Queens had little or no dead bees!!! These however are a little more on the Hygenic Carnolian side and less of Italian stock like the other hives i have. So maybe this is the difference??? Something to think about. Liek i said i am not worried i saw this last year and i had 100% overwinter! So i will keep my fingers crossed. If we had warm days you possibly wouldnt notice the dead bees b/c the workers would have removed them hiding this death toll from you.