Just to add, I imagine as a 12 year old he's super excited and checking on the snakes often. If they're problem feeders or being difficult, I will pretty much leave them alone as much as possible. I will only check on them/disturb them every other day just to make sure they have water and it isn't soiled, etc.
So you might just try feeding them (regardless if it works or not) and then just leaving them alone only to make sure they're OK. I wouldn't take them out, handle them, look at them too much, etc. I think sometimes they're just so small they get freaked easily and isolation is best.
Just something else to think about. But out of hundreds of corns I've hatched, there have been maybe 5-6 that never ate and eventually died. With a little patience and tricks, you'll have these guys up and feeding in no time.