Went to check my hives yesterday, and one of them had several hundred bees dead in front of the hive. It has been very hot and humid the last few days, and thunderstormed the night before, with a torential rain. I have noticed the last few days, that the bees were bearding up on the outside. I am thinking that they got cought outside during this storm, and were drowned. What do you think?
Sounds possible. Also after being cooped up they will have tossed out the dead that died during that few days.
Or, possibly, a robbing incident.
All possiblities. I've seen them from robbing, I've seen them from the beard getting suddenly caught, but a gentle start to the rain and they all get inside. I've seen them like that from inceticides and mites too.