thats going to be a serious issue for the place when a kid cant move his hand out of the way fast enough. ive been bitten by my oscar before, and he's drawn blood. i can easily see some crazy parent suing the place for it after their kid gets a few drops of blood drawn.
I once opened the lid to my tank, grabbed the bag of fish food, and my Oscar jumped out of the tank, hit me in the chest, and fell on the floor. He's a bastard.