I never heard of bees with nests in the ground either, especially not in
the Black Hills of South Dakota. Yesterday we unloaded the horses at a trailhead
for Old Baldy in the northern Hills, decided to let the horses stretch their
legs and grab a bite before saddling up. My mare put her head down in a patch of
grass at the edge of the gravel, snorted and jumped back hard. I looked down for
cactus and saw bees boiling out of a hole. We took the horses and rapidly got
them away from the area for a bit, then I moved the trailer. Just added to my
knowledge!