I feed 1 appropriate size rat/mouse close to widest part of the snakes body. For example I have 09 babies that are 80-100 gram range on adult mice every fifth day.Once they gain size I switch them to small rats and then on upto medium rats every on a 7 day schedule.This works for me. If you have a scale, What is the weight of your snake? As far as substrate I prefer unprinted newspaper for my racks. When I'm spot cleaning its easier to see on the paper compared to shavings.