alot of things can come into play.first of all can you post a pic of his tank/tub?second those mice are not consumable in my opinion.its a shame he is leaving soon because i think you should feed live for at least a month.what are your concerns about feeding live?it is actually more inhumane to kill the mice unless you have a co2 chamber.snakes make quik work of there prey and it is a natural thing.i would suggest live hopper mice or live pinkey rats until he has adapted to his new home and gets used to eating every 7 days,then i would try to find some f/t from a reputable place.