bi color blenny is a coral eater!

[One_Divided]

Well I went to check on my tank today to find an unpleasant surprise. One of my acos and a couple of my caps are covered in mouth marks which are identicle in shape and size to the bi color blenny's mouth. I added him about 3 days ago.. I would have still been doubtful that it was him untill I saw it make some new bite marks..

Now I just need to catch the bugger.. Any ideas? I've tried taking out the cap he's on, but he just swims out right away to a little hole in a huge rock. I would take the rock out, but then I'd have to tear apart the entire tank..