Try feeding them by hand so they get used to your actual hand. Then introduce your hand with no food and get them used to exploring your hand. From there you can pick them up while they are exploring. Slow baby-steps with this and they should be fine. I have always heard that T.infernalis can be a bit jumpy so be aware of that. In my years working with Thamnophis I've learned that in most situations the females seem to be the ones they can be the calmest. The males have an attitude of leave me alone unless you are offering food or a female at breeding time.