The poem
Under the leaves, under the first loose levels of earth they're there -- quick as beetles, blind as bats, shy as hares but seen less than these -- traveling among the pale girders of appleroot, rockshelf, nests of insects and black pastures of bulbs peppery and packed full of the sweetest food: spring flowers. Field after field you can see the traceries of their long lonely walks, then the rains blur even this frail hint of them -- so excitable, so plush, so willing to continue generation after generation accomplishing nothing but their brief physical lives as they live and die, pushing and shoving with their stubborn muzzles against the whole earth, finding it delicious.

I thought this poem really caught the essence of a mole
I loved it!
the mole is without doubt the finest literary achievement by Mary Oliver on the subject of underground animals since the great flood.
It is not a very good poem in my optics however.
Even in poetry, I like animals to be animals, even humans to be animals, but not animals to be humans.
For me, the key phrase is "accomplishing nothing". It rings so true, at first, because I've never thought of a mole as really "accomplishing" anything, but then I think, "what has humankind ever accomplished that's so important?"