Back in 2010, I visited an old time beekeeper who had about 70 hives in his front yard. He looked like he had been in the boxing rink for 12 rounds. His face was all swelled up. After talking to him for about an hour, I asked him what had happened. He was cutting his grass around the hives like he had hundreds of times but this time it was starting to rain. They really tore him up. I think it is the pressure change that really irritates them.
Jim