He always attacks my hand by biting it when I stick it in the tank to rearange things, but today he let me rub his head without flinching! Not just once but all the time now! Nothing is wrong with him. I guess he likes me.
I've never tried to pet my fish, but some will eat from my fingers. Which I assume is a sign that they trust me well enough. It does make it easier to get food to the right fish. My rasboras today nipped at my arms when I was trying to feed the angel I put in their tank--I thought only my barbs did that.
Its fun when you hand feed them and pet them. I have a angel that eats out of my hand and I can pet her too! Sometimes my Three-Spot Gourami or my Convict Cichlid will eat out of my hand too.