Honey bees will almost never land on you, unless to sting. If you are being stung by Africanized ("killer") bees they are already alerted. Flee far and fast, as it is your only defense. It is true that crushing a bee's body releases a chemical (I think it's formic acid) that is a warning/alarm to other bees. But, this really only pertains to it occurring in close proximity to their nest. If you crush a bee 100 feet or yards from the colony it will not cause a general attack, as your query would seem to ask. Africanized honey bees are very dangerous and impossible in the field to distinguish from our Italian honey bees. The extreme aggression is the only real clue, but then it is too late. I hope I have answered your question. If not, feel free to e-mail me as I will help in any way I can. Be careful, but there is no need to live in fear of them.