Out of the world’s 20,000 or so species, most bees are solitary. This means that rather than living in a large hive like honey bees do, most nesting bees are hardworking single moms providing nectar and pollen for a few eggs at a time. After she has provisioned food for each egg (in the form of a little round or square loaf that she has molded herself from the pollen that she has collected), the mother seals off the nesting chamber. Once she has completed her work, she will no longer remain with the nest.
The vast majority of these solitary bees nest in the ground, which means they need a safe place to lay their eggs. By allowing a corner of your backyard or local park to remain a little messy with leaves, taller grass, or hard-packed soil, you’ll provide a place for them to build their nests.
It is also worth noting that most of the world’s bees are too small to sting and, unlike honey bees which have a colony to defend, it is very risky for a solitary bee to sting. If a mother bee stings and is swatted and killed after doing so, her young will perish without her. And you might be surprised to learn that no male bees have stingers.