When was the last time you were in that hive?
Last weekend, I was in one hive that was missing a frame. I pulled out a new undrawn medium frame and tried to install it. It would not go down far enough. I pushed it down and heard some crunching. The bees boiled out and nailed both hands and chased me away from the hive. I had to rubbed my hands in the grass to get rid of the banana odor because every time i tried to reach in the hive, they attacked my hands. I looked at the super and realized it was the only shallow left in my apiary and removed the frame. Later I was cutting the grass in front of the apiary. On the third pass they attacked my head. This is unusual for my bees but it was the same hive that I had crushed a bunch of them under the frame. I let them settle down for a while and started cutting about 50 feet from the hive and they were in my hair again. Every time I tried to cut that field, 3 or 4 would attack. I ended up putting my suit on to finish the job. I have found that my bees treat me like I treat them. If I am gentle, they are gentle, if I am rough, they are rough. It may take 3 weeks for that hive to settle down. The flying bees will have died off by then.
Jim