I'm actually curious about how long it takes for them to become "feeder-sized" for an adult BP Auryn's decided that live are all he wants...and PetCo's mice are pretty puny. I've been buying them 3 weeks in advance (keeping 6 at a time), and feeding them up to a bigger size. I'm thinking this summer I might start breeding...but depending on how long it takes for them to grow, it might not be a great idea (I only have one BP!). It's pretty awesome how they just sprouted hair over night!