I put a small piece of shrimp on one of them. It looked like it moved a little but it didn't eat it. I will have to try shutting off the powerhead and see if that would make it easier.
Yup hairy mushroom coral. Medium light requirements. Photosynthesis and will eat smaller meaty foods. Aggressive to other coral and will propagate very easily, too easy some will say. Have seen them take over a tank.