I have a beautiful female Japanese Swallowtail angel in my reef tank and she hasn't touched anything. I also have a coral beauty who has a liking to my colt coral, nips at it...it retracts, but comes back out, so I'm not sure if it actually does any harm. Other than the occasional nip they are both pretty safe......at least in my tank. All angels have a potential to be holy terrors in a reef all you eat buffet atmosphere, but I have been lucky with these two.