Mine dont but then i never tried. Its not that im scared or anything of them stinging me i just never felt the urge to do it. I have my hands in the tank sometimes and the rays dont seem to be bothered by me but im always on the alert incase 1 of them spooks which has happened and frightened the c@*p out of me. Dont forget my tank is 4 foot wide and when your leaning that far over its not easy to move quickly. Ive read on here that a lot of people hand feed their rays, i think its down to the individual and the rays. Good luck if you try it and be safe. 
