when your snake gets full grown, which assuming its not if your feeding it one mouse a week(for an adult 1 mouse is a tease), you will be finding yourself feeding it more like 4 mice at a time to keep your pet satiated, your best bet is to get on rats asap, that way when he's full grown, 1 medium rat every 10 days or so will do him/her perfectly fine, without having a ginormous feeding bill, hope this helps