I don't really remember mine being 13 grams, but as an adult, she lives in an 18x18x24 exo-terra all by herself (this is roughly 33-34 gallons). It's cluttered up with a bunch of leaves, a couple of those corner hammocks, a hide down on the ground, etc. Basically, I think a big cage isn't going to be a problem as long as there's enough clutter that you occasionally can't find the animal in it without opening it up and digging around. :)