I checked my hive yesterday for the second time this year and noticed some changes from 10 days ago. There are considerablly less bees and seven of them looked very old, with dark bodies and only sticks for wings. I looked close for mites but saw none.
There are three to four frames of capped brood, lots of pollen and honey stores. My queen is alive and well. I have also noticed few, very few, foraging bees as compared to two weeks ago.

My question is this: Is what I am seeing just the winter die off or do I need to look closer??
Other than the above, the hive seems healthy.
Any thoughts?