Relatively little is known about the nesting requirements of ground-nesting wild bees, although nesting sites are of central importance for most wild bee species. There are almost 600 wild bee species in Germany and 75% nest in the soil. To date, however, most of the research has concentrated on the wild bee species that nest above ground in cavities.
Click here for original story, Vegetation-free patches encourage ground-nesting wild bees
Source: Phys.org