Angelfish Fighting W Tail?

[reef aquatics 101]

When my blue tang goes in cave the emperor sometimes try to hit him with his tail. Is this normal. my blue tang is bigger and he usually doesn't fight him in the open. Is hitting with tail normal for a emperor angelfish.. Also one of my clownfish wont leave my baby blue tang alone anyone know why. He keeps chasing him.

 

[Wen]

When my blue tang goes in cave the emperor sometimes try to hit him with his tail. Is this normal. my blue tang is bigger and he usually doesn't fight him in the open. Is hitting with tail normal for a emperor angelfish.

When I vacuum near a specific rock cave, my emperor gets mad. He grunts and try’s slapping the gravel vac with its tail too.
I wondered about that behavior as well.
Guess it’s normal.