Just recently, there was a news story here in the UK regarding newspaper and food packaging. The warning was that newspapers contain mineral oils and this is also recycled into food packaging. The discussion was that this could potentially cause health issues in humans and I worried after hearing this as I use a sheet of newspaper to line the top shelf of my cage, which helps catch any urine. I used to shred newspaper into bedding material, but stopped doing that. I now use a paper based bedding called PetLife paper wool (it`s not wool it`s strips of fine white parchment) so I don`t know whay they call it `wool`! :roll:
My advice would be, ditch the newspaper and look in your local pet stores for a safe, paper based bedding material. I`m not sure what`s available in the states, but you will know a paper based bedding when you see it. That woolly stuff is dangerous so don`t touch that.
As for your substrate, Aspen is said to be okay, but I`ve never used it myself because it`s a shavings type of wood. Apart from Aspen and the dreaded Carefresh, I`m not too sure what else you guys use over there?
Don`t feed your mice corn or soya. Both are proven to be cancer producing in mice, so always check the packaging. Corn or maize are the yellow flakes in food mixes and soya might take the form of an extruded biscuit of flakes. If a food contains soya or corn that can be picked out, just do that. But sometimes soya or soy will be sprayed onto the food and you can`t eliminate it, so read the ingredients list and packaging carefully before you buy.