Most animals take awhile before they're willing to test out the new hide in their enviorment. Some will obviously take to it more quickly than others...but the only real suggestion is to just give it time...and like Kaorte said, perhaps putting him in the hide to jump start the process.

I ended up making a hide for my one leopard gecko the other day...put it in the enclosure, and to my shock my gecko walked into it immediately and settled down. New things tend to excite that little girl though. All you have to do is arrange her cage differently and she'll walk around exploring it for the rest of the day haha.

Regards,
Josh