What should I do with this mystery worm??

So my first ever tarrerium has been going stable for quite a few months now, and a while ago I noticed some odd but small tunnel formations showing up in the soil.

I assumed this was just the bigger orange springtails I keep using certain paths consistently. But today? Today I learnt what was really making the tunnels.

A worm! And not a small one either, it spams up to several inches now. I only noticed it cause I watered the tarrerium again and noticed it come up and into the moss.

I have no clue where it came from, I bought from specifically sterilised soil, however I did use some wild moss, a lot of plants and a wide range of decaying matter such as rotting wood, leaf litter and the very occasional food scraps. So I suppose its well fed and well kept.

But I'm not sure what kind of worm it is, I'm inclined to believe it's just a normal one, but I'm afraid of how big this guy might get. It's a large jar but I worry it'll outgrow it. The springtails don't really seem to mind, but I'm unsure if the worm waste is of any worth to them, would they eat it?

I'm not sure if I should leave it be or try and retrieve it the next time I notice the squiggly resident.

Any input is greatly appreciated