During the day I keep them in the cage, one that I put cardboard on all sides and top, and a towel I clip on and hang down, they love it and feel secure in their dark burrow.
At night before I crawl in bed I open the cage, grab both and stick em under the covers, its a game we play they run up and down the bed rubbing against my legs and I endlessly pet and scratch them.
When I'm just about ready to drop off, I lower em to the floor and they're off for a night of adventure.
These particular Rats have shown no desire to chew anything other than paper or cardboard, and my shoes. I have litter boxes everywhere and they have a ladder up to they're cage where there is plenty grub.
They fool around till about 3 or 4 AM then I feel things moving around in bed, either I let em stay or lock em in the cage and finish sleeping.
I realize this isn't for everyone, as I gotta wash bedding forever and bathe more than I like. But hey, I'm an old batchelor who lives in a 1 room flat, who's a slob anyways and hates the way they look at me when I lock their cage.
Spider
I really think Rats who chew alot on unnatural stuff have some kind of deficiency they crave like zinc or iron etc.