Q.Small black worms
I keep finding these tiny (less than an inch-long) wiry-looking black worms when I dig in the garden. They curl up in a tight spiral when disturbed. I’ve been finding them in the same locations as slugs, which I’ve been trapping with beer traps. When I lift the trap to empty it, I see lots of the little black worms. They’re not much bigger around than a pencil lead. I’ve looked at dozens of pictures of wireworms and millipedes and nothing is small enough or the right color!

They are a millipede.
https://www.gardeningknowhow.com/garden-how-to/beneficial/centipedes-and-millipedes.htm
https://extension.colostate.edu/pubs/insect/05552.html