Worms under sand picture

[savetheocean]

This is a picture from under the tank. All those lines aren't worms but small tunnels, the pinkish red ones are the worms. There has been like 5 times more holes and worms in the last couple months and I just want to know what they are.
Tell me if you need more shots.

 

[savetheocean]

They are really thin and have a dark red line going down the middle of them.

 

[TheAquarian]

It’s a mixed bag, I see bristle worms and spaghetti worms.

 

[ThunderGoose]

Some of them are bristle worms (as mentioned above). They're mixing up your sand bed. I consider them beneficial but the larger ones can sting you.