O ok, well the reasoning for my question is that my bp is now 380 grams and I bought my weaned rats in bulk but it seems like they all vary from 30 to 36 grams in size. Cannot find any from 38 to 45. So I was wondering was I under feeding my bp with giving him rats at 34 grams when he's 380grams. Then I was wonder should I offer two which would either equal or a little under the 20% so called rule.