usually you want to feed a prey that is the same size as the roundest part of the snake. i fed my ball a small adult mouse and she is a about a foot and half long. she took it easily but the mouse was a lil bigger then the roundest part of her body. they will suprise you, she suprised me today i was expecting her not to eat it cuz i thought it was too big. but if the mouse is bigger then the widest part of the snake it could break her ribs