ID assistance needed (weird worm looking thing)

[Blue Baron]

So . . . these have started spreading quite well as of late. They're hard, don't move around . . . and appear to MAYBE have a tiny little bit of something that sticks out the end. There's tons of them, and they're starting to grow everywhere. I haven't noticed any detrimental affects, just curious as to what they are.

 

[steve-s]

If they are hard calcerous tubes they are Vermetid snails. If soft tubes, mini feather dusters.