I read in a few forums people really like using soil over the pet store bedding. I'll probably give it a try when Home Depot sells topsoil again in the spring. $1.50 a bag

http://www.petshub.com/forums/topic/soil-as-a-substrate

http://www.gentlechristianmothers.co.../t-165697.html

https://www.reddit.com/r/PetMice/com..._as_substrate/