it realy does depend on the fish. If you get a snowflake, you should be fine with hermits, but with anythign else, it would depend on the fish. Ive even seen niger triggers in a reef tank, somewhere on this site from someones tank....dont realy remember. My snowflake gets along great with everyone, he gets mad at my valentini during feeding time though because he is eating all of his krill.... But besides that, hes behaved himself.