How long have you actually had him? If you bought him from someone else, he may not yet have gotten adjusted enough to his new home to feel safe and secure. He may just be scared. After all, he's a baby and in the wild a baby snake usually gets eaten when something picks it up!!!!
My first baby corn I ever got was so shy, I kept her viv covered by a towel so that 3/4 of it was dark. She didn't eat for the first month I had her, and after that for the next 2 to 3 months, I had to completely cover her viv when I fed her, to get her to eat. I named her "Shy" because she was such a shy baby.
I didn't even try to pick her up for the first month I had her (she was obviously healthy-if she had given me any reason to worry about her health, I would of course have handled her to inspect her condition, etc.) I simply let her get used to her new situation at her own pace. Gradually she started getting curious and as she showed interest in coming out into the uncovered part of her viv, I also reduced the amount of the viv that I kept covered.
Once Shy was confident enough to stay in the uncovered area even when she knew I was looking at her, I started picking her up and holding her for very short periods of time. I was always careful to pick her up so she was well supported and didn't dangle, trying to make her feel as secure as possible. I would gently stroke the top of her head while holding her, then gently put her back in her viv. After a few times of this, she became more relaxed when she was picked up and started crawling on my hand and arm, curiously wanting to explore.
Now Shy is a big 2 year old, so confident I can take her visiting at the local pet shop. I hold her as I walk around and she shows clear curious interest in checking out brightly colored objects. She is calm and confidently at ease when other people want to pet her. To look at her confident easygoing behavior now, one would never have guessed she started out as such a timid baby!
As a baby Shy wouldn't eat unless her viv was totally covered with a towel. At 2 years of age, when hungry, she will take live mice fed one at a time, from my hand (and would be great to use if anyone wanted a demonstration of how a corn snake grabs, constricts, and eats live prey, when she's hungry Shy not only reliably will eat, she will do a little "begging dance" to show me she wants me to feed her. Interestingly, she has two feeding styles. When fed live prey, she's very careful to strike the head of the prey. When I've fed her baby rats, which tend to fight back more aggressively than mice, I've observed a very interesting behavior. I'm not sure how she does it, but somehow when Shy is fed a live young rat, she manages always to position it so the rat's mouth is jammed into the substrate and also positions her coils so the rat's feet flail helplessly out of reach of her own body.
However when I feed Shy frozen/thawed mice, I serve them on a gray cream cheese container lid (her preference, she will ignore them if I serve them on any other lid!!!) Shy's eating style is totally different when served frozen/thawed. She waits until I set the lid holding her food, down on the floor. Then she casually goes over and just grabs the mice any old way and eats them. No need to bother grabbing head first, etc, when she knows for sure there's no chance of them retaliating!!!
I got some new baby corns earlier this year, along with a couple that were older. These two new babies were as different in personality as day and night. The baby caramel girl is outgoing and sociable, the baby amel boy I got at the same time is shy and nervous. He will rattle and show defensive aggression even after I've had him a few months, when I first go to pick him up. However once I pick him up and am holding him, he relaxes and then is curious and enjoys being held and carried around the house.
I've found all the corns, once they adjusted and became more confident, enjoy inspecting brightly colored objects. I've had corns get restless in their cages at times when I knew they weren't hungry and on a hunch they might be bored, I started putting colorful pictures up on either on the back or side of their tanks, or sometimes just lay a magazine with a bright cover on top of their screen lids. Every time, they have settled down to checking out the picture. I've found the same thing with the garters, if anything, they are more curious than the corns. Right now, the front page of the Sunday newspaper comics has been spread across the top of the garter cage for a couple of days, and every so often I will see one of the snakes checking it out. The garters also enjoy looking at their reflection in the mirror. So far though, none of the corns has showed interest in the mirror.