I was thinking about mice farms. Manufacturers could set that up and the mice would quickly grow to adulthood. They'd require little space too if they were stacked high shelf-by-shelf. Do it! You can go on Shark Tank and Bonita and I will be customers. .I assume mice based pet food never hit the market because no one runs mice farms. Other meats can be dual-purposed for pet food and other things but mice would have to be Pet specific.
In other news, I just thought of a great new business if anyone wants to partner with me ...