Generally BPs will feel secure with a one way in, one way out kind of hide. There are several on the market from Exo Terra and from Reptile Basics.

http://www.exo-terra.com/en/products/reptile_cave.php
http://www.reptilebasics.com/hide-boxes

You can also make them from small dish tubs from Walmart or cookie tins. I've seen both.

Dave