what are these?

[Prairie Reef]

hi everyone, i noticed these little creatures a few weeks ago, they appear to have little round heads on stalks with hairs all around the head, they’re probably only a couple millimetres tall, they’re also purple, can’t seem to find what they are , sorry about the picture quality it’s the best i can get. thanks everyone for the help.

 

[lapin]

Small filter feeder worms. In my tank they have hard white tubes attached to rocks