They're clay flower pot bottoms...low, snug, and small. He's 3 months old and around 300 grams or so. I've put him in the hides before, and they fit him snug, so I don't think the hides are the problem. I guess it's just his preferences or something.

Ooh, wait...what about scent. Would that affect it? Those hides were used by my female a year ago when she was a baby. I've washed the hides under water, but never gave them a big scrub or used a cleaner or anything. Could he be smelling another snake and shying away from them for that reason?