That is a lovely pic of Hissy, cant believe the way he is balancing up there all curled up! I know corns are not supposed to be arboreal, but I think our corns often prove that wrong!
They do love the trees we didnt know whether to put them in but when we got Cinnamon he was in a smallish RUB with plants in and he was sat in them really cosy looking so we bought the plants to make him feel more at home