Ground-dwelling mining bees are among the first pollinators to emerge each spring, perfectly timed with early bloomers like crocus. Of the nearly 4,000 species of native bees in North America, about 70% are ground-dwellers — solitary, gentle, and essential. They nest in small burrows in bare or sandy soil, asking for little while giving back so much to the garden ecosystems around them. A patch of open earth is all they need.