I had read somewhere that Africanized bees often give a warning before attacking if they encounter you before you’ve breached the attack zone around their nest. The warning they give is to repeatedly fly into you at high velocity without stinging. If you approach their nest further, they’ll resort to stinging.
Fortunately, I read this not long before I experienced this phenomenon on a limestone crag near my house. Rather than immediately start running, I took a split second to locate their nest first to make sure I’d be running away from it when I bolted. The bees only followed me for about 100 yards downhill, continuing their kamikaze behavior, before returning to their nest. They did not land on me, so I did not try to swat them away, and I was never stung during the incident.
Perhaps there are some bee experts on the discussion board who can verify the truth of this warning behavior in Africanized bees. If it’s true, it might be worthwhile to keep it in mind and make sure you don’t stand and try to swat away bees if you encounter them doing this. Some folks might try that as a natural reaction, especially if they sense only a few bees hitting them at first. My guess is, any such aggressive counter behavior might provoke the bees to start stinging.