Ground black bees
These are bumble bees in a nest; their nests tend to be small and hidden in the ground, though perhaps something brushed aside the dead grass that typically covers the nest. They are tending to their brood in the cells.
That 'something' was my husband......should I attempt to put the grass back? I realized how little I knew about bees when I tried to ID these guys online. Thanks so much!
It probably wouldn't hurt to gently put some grass back, at least lightly. The bees may be able to cover the nest back up themselves, but we cannot say for sure.