Could be bad. We've hit bee hives when pushing rotten trees around. We hit some sort of black bee hive. While they seemed po'd, they didn't come after us with a fury. We got about 50' away and all was safe.
I got hit by some hornets in a ground nest a few years ago. It's an event you don't soon forget. Always wonder when I will find another set-up like that. You can't see 'em all. I do wish I had a cab tractor for that very reason.......and a/c would be another reason. ;)