Bristle worms

[FishyFishy!]

The big thing is that they eat detritis. When I find that they are overpopulating my display, I pull them out and put them in my sump/fuge, or get a 6 line to eat them up. I find them harmless (until you get poked by one... then I hate them).

The only time that I worry about them is if they are massive (bigger than 4" long or 1/2 cm thick) or if they look like fire or enucid worms, then they get flushed.