I usually let them go a month or until they seem to be getting skinny. Most will eat before then. It's really a judgement call and tough to explain over the net. I try different food items twice a week. Sometimes they are shy and that's why I like the hidebox and a pink rat that doesn't move around so much like a hopper mouse does. Assist feed when you get concerned but don't let them go too far. I know that's not the best answer but it's tough without seeing the snake. Some hatch chubby and are fine for a while.