The bee cluster has moved to a part of the frames with capped honey. The bees are tearing open the wax cappings to get at the honey. The little pieces of wax cappings fall to the floor of the hive (or through the screen bottom). This sounds normal.
I don't know how warm your weather has been, but if your hive has been experiencing robbing, you will also see many tiny wax pieces. (but you will also see many dead bees from the fighting.)
I don't know how warm your weather has been, but if your hive has been experiencing robbing, you will also see many tiny wax pieces. (but you will also see many dead bees from the fighting.)