The bee kingdom has two different types of bees; social (honey bees, bumble bees), and solitary (where every female is a queen and they assume all duties.)
The bee kingdom lives in three types of environments; hives they create (honey bees, paper wasps), holes in the ground (bumble bees, miner bees) and holes in trees & reeds (mason bees, leaf cutters). There are Thousands of species of bees, hornets, and wasps throughout the world!
In general, social bees, hornets, and wasps work in a community where each has their own job. Where we get in trouble is with the hive defenders. “Protect the queen & our babies” is their rallying cry! And stinging occurs…
The solitary bee, on the other hand, has no workers and little to defend. If she guarded her nest, she wouldn’t be able to gather pollen. As a result, it’s EXTREMELY hard to get stung by a solitary bee! When your hand or head gets in the way of her hole, she simply 
hovers, goes around you, or flies away to find her hole later.