Anyone else's trigger do this?

When my blueline and humahuma triggers are looking for something to do they run around the tank slamming there tails up against things. They will slow down, look at what they want to hit and side swipe it good. Anyone have triggers that do this? Its a daily occurrence here.

 

I used to have a mini trigger and never noticed it doing that. I have seen other fish do that and based on my research it is the fish trying to remove parasites from their slime coat... Not sure if that is the case for you or if the fish are just trying to hit something as triggers are aggressive.

 

Well i should mention they usually do it if there is bubbles on the rocks to knock off. Or pissed off, i know it sounds funny but, people out there will know what im saying. Its easy to tell if a trigger is pissed. They have no parasites as far as i know. Nothing visable or anything that would affect eating or behavior. Although I do know what your saying and have read that as well.