We breed and feed rats,ASF's, mice and gerbils to approx 300 snakes and, with the exeption of gerbils -kept to feed six LTC females which refuse to eat anything else, the remainder take rats, multies or mice dependent upon the size of the snake. A small number will only accept one of the three or two species from the three.
I think it is important to have a few choices available, sometimes preference is given to one prey species than the others, so we keep a choice available all of the time and freeze 'overspill'.