They get to about 7-9 inches including tail when fully grown, they are similar to the size of a large mouse. Um... temperment, mine were really friendly until they started breeding and then they were the spawn of satin and would dive at your hand just to take a chunk out, but would soon settle once the young were weened again, defensive parent mode i think. They young when handled from an early age can become very "tame" and sweet. they are as inteligent as a normal rat i would say but do not have the same friendly characteristics unfortunately. They are semi arborial as well so require a tall cage rather than long, half meter by half meter by a meter tall is what i would say is the minium for these guys and like their cousins they need to be kept with at least one other acacia rat, colonies with one male are better or a full female colony.