My fish keep scratching themsleve against the rocks in my tank. wuts bugging me is that i cant see anything on their bodies or anything wrong with them for that matter, yet they still rub.
Fish can get itches, and do this to relieve themselfs.. However, if they do it all on a constant basis, it can be trouble. It's not a completely normal behavior, when being done often. What are your water paramaters? Extended periods of high nitrates I have noticed will cause this too..