Up until now I've followed the 10-15% guideline without an issue. However, my boy is about a year old and a little over 500g. My last order from Big Cheese was weaned rats (35-49g per their website). The rats aren't quite as thick as he is though. Should I feed more often than 7-10 days? Should I double up? Finally, after this order is used up should I move him to smalls? I doubt he would ever eat beyond smalls.