I think almost everybody has managed to lose a snake in the terrarium at some point.
The first thing my parietalis female did, was to squeeze her way in between the floors. I had raised the floor of the terrarium I was keeping my snakes in, and between the real floor and the upper one, was a 21mm high "crawl space". The male hadn't found it during the 6 or so months he had been living there, but it took the female about a minute to squeeze through in a corner where I hadn't cut the upper floor that precisely. I wouldn't have found her, if her nose hadn't been sticking out.
I ended up bored and having too much spare time, again and here's the result:
