Handdoni nems will eat fish that touch their tentacles. Their sting is very potent from what I've heard. Tangs, angels, gobies, and dragonets are common treats. If you want a nem that will live in the sand look into a M. doreensis. They are a little bit more difficult to care for than a BTA, but won't eat as many fish as a handdoni will. Hopefully Todd comes in on this one.