Except for black milks, I always had to get a mouse colony going at milk hatching time. They are Lampropeltis, but most of them sure don't have the feeding response of kings! In the dark, in a deli, with an appropriate sized live pink was what I've had the best luck with. Also, no water or substrate in the feeding deli. You want the baby wandering and running into the pink over and over, not hiding and holding still on the other side of the container. Try a light boil or braining if frozen is all you have, but I'd start hunting some live pinks -or better yet a very pregnant mouse. You're gonna need them small!