We are going to be switching to rats soon. We have our breeders ready, just waiting for the females to get a little bigger, and we still have quite a few mice left. Within a couple of months she should be on rats. Does the 10% rule still apply into adulthood though? I have seen people say they feed 2000+ gram bp's only 3 or 4 mice every two weeks. My 900 gram has been getting more than that.