Although we don't see any insects in the photos, we think this is a Yellowjacket nest site. Some species of Yellowjacket (a wasp, not a bee) nest in the ground, though other species nest in tree cavities or in open-air nests attached to dense shrub branches or similar locations. Ground-nesting Yellowjackets often take over a disused rodent burrow or rabbit hideaway. While there are plenty of ground-nesting bees (most of our native species fall into this category), they are solitary, so will not share a communal nest; instead, each female creates and provisions her own burrow for her eggs, and she leaves or dies when her task is complete.

The piece of visible comb (the papery gray material that looks like honeycomb) visible off to one side suggests that this nest has already been plundered by a predator eating the larvae within it, or perhaps was dug-into by someone else, since comb would not be constructed outside of an in-ground nest otherwise. Although the same shape as honeycomb, bee honeycomb is made out of beeswax while wasp comb is made out of wood pulp fibers, essentially a natural paper. Honey bee comb stores honey or larvae, whereas wasp comb only house larvae because they do not make or store honey. Wasp comb will disintegrate on its own over time from exposure to the elements or from being picked-apart by various wild animals. (Some birds even include it in their nests.)

All social wasps -- those sharing one nest, like paper wasps, hornets, and yellowjackets -- will die out very shortly now that we've entered autumn. A few young queens (mated females) will depart the nest and find their own overwintering site somewhere else, where they spend the winter alone, and the rest of the colony members die by late autumn, if not sooner. Nests are not re-used from year to year. If wasp activity has waned or ceased enough that you can stand at the presumed nest entrance and not be stung by defensive wasps, then you probably don't need to worry about treating it with wasp spray, and the nest might already be functionally abandoned. You can fill in the hole (if you want) at any point in that case; otherwise, wait until winter or any time after the wasps end activity.

Another explanation is that the comb is from a Baldfaced Hornet nest (maybe not directly overhead, but in the general area) that fell down and fell apart due to predator activity. European Hornets make a similar-looking nest and comb, but it will be tucked inside a tree hollow or another sheltered site, so unless something dug-out the nest and tossed comb on the ground, it wouldn't be very visible. The cells in this comb look fairly small, though, so we think it more likely it's from a Yellowjacket nest (as they are about the same body size as a honey bee) compared to a hornet nest (which are at least twice a honey bee's body size).

Miri