• Allison

Shawn

Aren't they hydroids?

Jennifer5784

Well, this is definitely not algae. How can algae hide when touched? Maybe it's worms, but it would be better to look at a couple of photos and determine.

Christopher1252

No, these have a column (body), but mine do not.

Heather

You touch the little stone, and they crawl into the stone, and after a couple of minutes, they come out again. It grows like thin grass. I'll try to take a photo in the evening; the phone doesn't have macro shooting, so it will be hard to see. Well, I'll do something!

Chelsea567

there are also on other stones