Can someone please tell me what these are? They appear to be spreading to
Other rocks and I’m wondering if I need to get the badly infested rocks out of the tank?
Some folks have luck with Bumble Bee snails for control of these pests. Yours look like the most evil, the ones that irritate corals and puncture stab wounds into your hands and fingers while working inside the tank.
If you could remove all the rocks I would, but sadly these things spread everywhere, and fast if they are already spreading it is likely too late?