bristle worm. hitchikers. not a problem. They'll take care of any dead or dying critters. You'll rarely ever see them, only at night or when you feed they might stick there body out to try to grab some food.
Love them already, as long as they are good. I also noticed a fer very small thing that are clear, way to small to picture, but look like feather duster other then being clear. Do feather dusters start out this way?