I have two stubborn boys right now that have refused rats.. (ima smack em if they dont get over that..) They are both right at 400g each (gaining weight fast as well) and they are currently at 3 large mice at each feeding. Still costs less than two rats.. but rather a pain in the butt.. Im going to try and get some ASF and see if they will switch over to those. Ive got like 15 babies and 4 preg female mice right now.. but good lord.. no way i can keep up with eating requirements as is.