can anybody ID these worms.. are they bad?

[aquaholic33]

 

[redox]

bristle worms and this must be a night time shot. They hide under the rocks durring the day and come out to eat at night ,no worries

 

[frungkis]

They look like the orange/gray mix ones. Harmless, very good detrivores. If there is too many, get an arrow crab they love them. Be sure to feed them or they will pick on your mushrooms. IMHO

 

[MetalReef9]

They break down detritus well, and can sometimes damage corals, depending on the species. Those look like the harmless ones.