In reading through the thread, you say you have fed adult mice. That being the case, your guy should be able to take pups no problem. If he gets big enough to switch to weanlings, then you can finish up the pups by offering him multiple animals at a single feeding or feed him at shorter intervals like every 5 days instead of once a week until the pups are gone. I usually do not switch to weanlings until they are about 350 grams.