baby corn snakes can get into very tight areas, so check cracks and tight areas around baseboards, even around the cage itself. Pretty much if its a quarter inch or bigger, there's a chance your snake can squeeze in.
Work from the top of his cage, checking around the lip of the cage, hood etc. Next anything within half the snake's length from the edge of his cage, check as well. if you house your snake in an aquarium on a stand, it will aim for the easiest way down or across. If in a container in a rack or on the floor, then it can easily head in any direction.
Snakes also tend to follow edges as well.
You can place a hide in a corner, with a thawed pinky inside to encourage it to come inside and eat and hopefully stay there. Make the hide nice and tight, even the same hide he had in his cage.
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PHLdyPayne