we have pet rats and consider them as much a part of our family as we would a dog.. seriously! (no kidding here) so to feed the very pet we pamper just seems wrong... we would honestly choose to have pet rats over having pet bp if it meant thats what they *had* to eat.. it very literally does come down to preference. the breeder has told us its going to take us FOREVER to get our female up to breeding size but oh well, would rather take a full two-three years to get her breeding size if it meant we could feed mice exclusively.. and to answer previous statement, i do not think mice are as friendly.. they stink too.