What bee is most likely to sting and why?

Bees are normally quite docile and will sting only if they feel threatened or in defence of their colony. Having said that, some bees can be a little more aggressive than others.

The most aggressive honey bee is the Africanized honey bee, the offspring of some Tanzanian honey bee queens which escaped from a research station in Brazil in the 1950s which mated with local European honey bee drones. Although a sting from an individual Africanized bee is no worse than a sting from a European bee, they sting much more readily and victims tend to receive stings from a large number of bees. Sensationalist media have given the Africanized honey bee the name 'killer bee'.