I'm switching my cats litter to wood shavings, pine,the kind people use in stalls and rodent cages. They seem to like it (I think it reminds them of my Moms garden mulch) , its cheap, and their box is in the garage, so mess doesn't matter. I thought I'd check on the internets to make sure it doesn't cause sudden death or anything. Anyone here have experience with this? My searches didn't yield any results.