I've been using shredded newspaper since last year with very little office paper. Haven't had any mudball issues but will keep an eye on it.I did the same thing last year to recycle shredded paper from work. I thought it was great- until mud mixed with the shredded paper and I'd have to take a manicure set to the coop to break off mud balls from toenails. Even with grit spread like gravel and deep litter started the mud would be found and the shredded paper held it together on their toes. Never had that issue before the paper and it stopped when I left the free nesting material at work. Hope it works out better for you than it did for me!![]()