I recently found out that the ink on newspaper is toxic. I was using shredded newspaper for all of my rodent bedding since I could get tons of it for free and shred it in my paper shredder. All of my white rats and mice turned a dirty black color. It affected the mice the worst, their testicles were swollen, they all looked very sickly, the new babies had short tails or no tails at all. I was amazed at how badly it affected them. I changed it out and started using Cypress mulch, all of the rodents recovered in a few weeks. I fed off all of the short tailed mice. Now I avoid even touching printed newspaper with my hands.
Wow I didn’t know. I only used it when I ran out of the normal substrate, and I stopped because he was getting ink on him.