Does anyone know what these little white things are?

[SinkyShippy]

I just notified them on the walls and equipment of my tank. I have not introduced anything into my tank for over a month and a half.

 

[Mr Fishface]

Those look like what I had in my tank when it was newer. Best I could tell they were just a type of tiny feather duster. If you look real close can you see what looks like a tiny feather duster at the end? If so then I believe these are beneficial to the tank!

 

[saltyhog]

Look up spirobid worms. Harmless but annoying little critters