Desjardini Tang nipping

[Devilutionz]

My desjardini tang (red sea sailfin tang) has been nipping at my leather corals, causing it all shrunk up.
I also saw it nipping at hermit crabs many other occassion.
Is this normal for a sailfin tang cuz none of my other tangs does this.

 

[coral diver]

No not Normal provably there is someting on the leather try putting some red or green leaf letuce in the tank

 

[happaman]

I've had tangs nibble on cloves/anthelia before but never a leather. I'd try nori or a herbivore food.

 

[Devilutionz]

I feed nori almost everyday but occasionally, I see it nip on my leathers. I flame angel wiped out the entire blue clove colony though