Hammer coral disappearing help!

[hillegom]

I have had this branching hammer coral close to a year. Have not added anything to the aquarium since. Yesterday I noticed a head was missing. Like the whole head on one branch. Today, same thing. What is going on?
Something must be eating this LPS.
Does anyone know if maybe a hitchhiker crab or worm would eat LPS?
I have not seen any, just wondering. I never see the fish anywhere near to nibbling on it.
Another one of these mysteries. I am going to set up a trap tonight.