Sow Bugs, Woodlice - they have lots of names, and there are over 3000 species of these little guys. I think I sacrifice a few of them to the gods every time I toss a log on the fire.
They are arthropods, in the subgroup of the usually-aquatic Crustaceans. They look like tiny Trilobites.
I am always happy to see these little bugs under logs and rocks. Arthropods own the world, even though we don't give them a vote.