We buy our mice 12 at a time from a LPS. My wife buys the little resealable plastic bags (small zip-loc bags)that are in the craft dept. at Wal-Mart. I get the job of seperating out the mice and stuffing them into the little bags, making sure i squeeze the air out of them. At feeding time, I fill up a tea cup with really warm water to the top and then put the bag with a mouse in it then put a small plate on the top to keep the mouse submerged.