I did an inspection on my strong back yard hive today. bright blue skies, no wind, warmest day of the year. The inspection started off fine, with perfectly calm little ladies, but five minutes later they decided to go on the offensive. I got to look through about 6 frames before I had to button things up because they were stinging my hands too much. I even thought of reaching for the veil for the first time in a year.
I am super slow and careful about my inspections and don't bang anything or squish the bees. I noticed this sort of "unprovoked" attack behaviour last spring too. All those grumpy old winter bees in the hive used to having their peace and quiet I guess.
As far as the hive goes, things are looking good. Found 2 frames of capped brood and 2 frames wall to wall with eggs. Not much in the way of in between larval stages, but I guess they could have been in the unexamined parts of the hive. Not bad considering the snow came off 10 days ago.