I have my ( 4) imitators in a 24"h X 18 X 18 exo ( screen pulled and replaced w/ glass) . They use every speck of space!
I think this the 12" cube is too small ?
Once the substrate is added it will reduce the available space left for the darts.

I originally purchased a 12"h X18 X18 for them and very quickly realized they needed ,more space.
They think they're tree frogs

check it out :
http://www.frogforum.net/general-dis...tml#post164971

Lynn