Help ID

[SLAYCHILD]

Hello everyone. I hope someone can tell me what they are, because I cant find anything on the internet. I will explain them the best I can. At night when the tank lights are off. I see these worm like things that are always stuck the the rock and seem to siphon the sand and once they are done they release the sand and it looks like sticks (pic inserted) Any help would be nice. Once again, I have never seen these thing before, even in my tank I had 3 years ago.

[dmweise]

I get those as well. Mine are bristle worms. Nothing to worry about. Its most likely the same thing you have.

[Mr Cob]

Wish you had a better pic. That doesn't look like a bristleworm to me. Bristleworms are flat. That looks round.

[Jonthefishguy]

what does the worm do as it moves. How does it retreat?

[dmweise]

That's just the sand casing formed when the worm moves through the sand.