I used KAYTEE Aspend Small Animal bedding for my Milks to burrow in.
Though, I use this one: http://www.drsfostersmith.com/produc...m?pcatid=11182
In my experience the KAYTEE Aspen bedding that's green on the outside had a bit more dust than this red one I found at a local feed store. Plus I got it at a great price and one bag has lasted me quite a while considering I only have two Milks I use it for.