Visible roundworms/nematodes in compost

[Lycopersica]

I thought I actually had apartment composting figured out. I put all my old root-filled potting soil in a huge transparent bag with some (non-diseased) plant debris, and a bunch of leftover tea leaves. The bag is sealable but I usually leave it wide open to keep it from going anaerobic and also to dry it out (I think I started with too much water). It doesn't smell bad, look moldy, or aggrevate my alergies. I sealed and stored the bag yesterday because I had guests. Imagine my surprise when I took it out this morning to find... more guests.

There were dozens of little white squiggles clinging to the inside of the bag. At first, I thought they were bits of old roots but then I realized they were moving. I'm pretty sure they're some kind of worm rather than insect larvae because they move like worms and don't seem to have legs. They're about the thickness of of a fine needle and at most two centimeters long. (The image below is magnified.) I think they came toward the surface because they were drawn by the moisture of the condensation.

Does anyone know what these worms are and how they got there? Are they a health hazard? Will they get out and infest my apartment? Or are they beneficial decomposers? What should I do about them?