snake defensive striking 101:

He's uneasy, so put him at ease.

1) double check husbandry
2) make him feel secure and at home by providing burrowing material and/or hides
3) make sure he is fed a solid healthy diet.
4) short, regular handling sessions (even just hook riding) will help him to calm down if the above 3 are met. You don't need to get bit, but don't let him 'learn' that biting you makes you go away, it only reinforces the biting response.