Thank you for your input, Gidi. I am aware of the shy and secretive nature of this species and I don't mind that. I have a male mandarin ratsnake (captive bred and born in '04) that I quite often do not get to see for weeks because he's hiding in the substrate. It's not that I want to handle my snakes every week or so, it's just that I like to handle them once in a while (say, once every 2 to 3 weeks) for just a couple of minutes so that I can admire their beauty from up close.
Judging on your and Kayvon's comment, I think that I will stick with my strategy to not handle the snake and to hope that he will become more calm when he ages.
Kind regards,
Bert

