When I got my girl the first feeding I did was rat pups. Shes been on rats since. Rats are larger than mice and will hold them longer between feedings than mice. We have a lps jere that charges pet rat prices for feeders because they don't breed their own and they don't like rats. With supervision you won't get the nasty bites. Mice are an advantage on the biting factor but then you have to think of the nutritional value also. Balls eat anything appropriate sized in the wild. Mine at approximately 2 ft was eating rat hoppers. I hated them because they moved too fast lol. Remember though if they were feeding 1 mouse every 2 weeks he's probably going to be hungry after waiting for his next meal. I fed every week at that size and still do, unless she's blued. Thats the only time she ever skipped a meal. On scales go to walmart or target which ever you have and get a scale there. Last time I looked they were around $20 or so. I need to pick a couple up myself. My girl after a forced fasting takes largish small rats at 3 1/2 yrs old. A friend has a ball that will take jumbo at the same age. That boy is fat though. Mine is on the skinny side until I get her back up to weight.