I'm starting to see a lot of very small red cones crop up around my tank. Anyone know what animal makes them? I'm sorry I don't have a photo, I can't get one worth using. They are attached to rocks, generally pointing horizontally, are red, about 1cm long, and look like tiny volcanos. I don't see any worm poking out during the day or at night, so I'm perplexed.
Thanks
Thanks