Just soft enough they mush together in the baggy. I defrost in ziplocks in warm water. Make sure you bring them up to a good temp together before you feed. I think it is the warm up that really gets the mouse stink on the rat. Also the hungrier the better. I try to make food changes a couple days after a shed or defecation. Good luck, I have heard some just will not convert but I have not had it happen to me yet.