bristle worms eat macro algae?

[Crys]

Hi,

 

I hate bristle worms, but I have said this more than once.  This morning I watch one eating some of my dragons tongue algae.  I watched for half an hour and it definitely ate it.   I have let the smaller ones stay in the tank because they are supposed to eat detritus, but if they start eating other stuff, I might get more cranky.  I saw one trying to get into the shell of a live snail a few months ago.  I  took out the worm.  The snail was not dyeing, because it still rooms around happily.   There is lots of detritus to eat in my tank so they don't need to snack on other things.  I am worried about having them  in the tank.  What are your thoughts?