So I ordered a few fleece cubes with a hole for them to climb in and some hammocks. Katsu examined and chewed various bits of his cube for awhile and then jumped in. Jump out. Jumped in. Then seemed to ignore it. This morning we found him sleeping like this
I'm not sure how he squished up there. Shortly after waking up his destructive nature then kicked in and he chewed 2 of the ropes that hang the cube. I figured that would happen eventually I just hoped he would take a few days.
Tomorrow get large, dull ended safety pins for holding the cube up. The hammocks I got have neat little pockets on either side for burrowing in to. I will have to get a pic but Keck is the only one taking advantage of that feature so far and she's camera shy.