I realize this about clowns, mine don't bite ... yet. BUT, I have a pair of yellow tailed damsels that nip at me. When they come at me I turn my hand towards them and flick my finger as if I was trying to shoot a marble. The little shock wave from my finger seems to be taken as a returned aggressive gesture and they back off. ................. Until I'm not watching, which is generally while I have a coral or something I want to be careful with in my hand. Then they attack and make me jump, I'm learning not to drop my beloved coral frag. You can't flick your finger at them when you are holding a coral frag, I think they figured that out. And it you think you can grab one while they are doing that so they can spend time out in the refugium, .. forget it.