Ground bees in MO. CO.
I have a very large presence of bees coming from the ground. There are hundreds of little mountains with a mouth in each mountain, I have applied several commercial products but nothing works. I contacted the MD agriculture department and they said that it looks like mining bees but did not recommend anything.
Montgomery County Maryland
Mining bees are beneficial solitary bees that aren't aggressive and are important pollinators. Their activity doesn't last long.
Here is our page about them: http://extension.umd.edu/hgic/mining-bees-lawns
We don't recommend poisoning them, but suggest modifying the habitat in which they are found. In this case, if it is in your lawn, thickening up or renovating your grass. The best time to do this is in late summer into fall.
Here is how to do that: https://extension.umd.edu//sites/extension.umd.edu/files/_images/programs/hgic/Publications/HG102%20...:
Otherwise, a thick groundcover or mulch in the area may dissuade them from nesting there.