Out of curiosity, how small of a hole could an average chinchilla fit through? Preferable a square shaped one. Would a 9 sq. in (3inx3in) be but enough for them to fit through?
Thread hijack. How likely is a chin to stick it's head through a 1.5" square hole that leads to nowhere when it has a whole room to run in? The room is animal proof except I'd like to use NIC/c&c panels to block off an area in the corner.