We had a bit of out of the cage time last night with the help of an underbed storage box. I slid it under the front ramp and he climbed down into it. At first he was trembling like a leaf, but after a few goes as soon as I put him back in his cage, he dashed back to the play area without hesitation. He burrowed in the litter, ran round inside a tube for rats, which he instantly loved, and rolled around and burrowed in a Chinchilla size sand bath. He climbed up the sides but didn't mind being gently carried back to the pen or his cage. I have to lift him into it as he's still a bit small to navigate the ramp safely, and the rungs are now a bit of a foot catcher, but he's getting more comfortable with being picked up as a result.