I'll agree with that. Some of my girls don't take for a month or two after they have been with the males. Then others will take right away and give me a litter of 13 the first time. BUT, I've only been holding back females from moms that have been giving me big litters at young ages. 3 generations in a row I've had the first time moms give me 13. It's weird, but I'm really liking my girls.