Problem Feeder Hatchlings:
I offer all hatchlings rat pups, typically more mobile pups as I find this stimulates a good feeding response. If I have a hatchling that does not feed on the pups after a several feeding attempts I will flip to hopper mice. Once they are eating consecutive meals I move them back to rat pups.
Problem feeders are not always a result of the snake though, husbandry can play a huge part in a snake that is not eating.
Hatchlings:
As mentioned above. We feed appropriately sized rat pups (the pups are roughly the same size or slightly bigger then the thickest section of the snake) every 5 days. Once we have the hatchlings on a solid feeding schedule we move to 5-7 days.
Holdbacks:
All depends on the size of the snake and remember it is not a race! Again, we feed an appropriate sized prey item on a 5 to 7 day feeding schedule for hatchlings and a 7 day schedule for juveniles and adults. During breeding season our feeding pattern fluctuates depending on the animal.
All of our animals feed on live rats, no F/T here.