There are people around here that sell them online, and that's what they start with, thousands of meal worms and use huge containers. They usually have them in their garage. I have mine in the house on top the long craft hutch in the ??? room of the house. (We do have dampness that causes a lot of mold, so I do change out their food every day and put the potato etc on a cardboard on a plastic lid 1/2.)
But I didn't start with huge amounts (with 5 gliders and no intent to sell, there is no reason for most of us to have a huge set up)
I started with 2 large containers of giant meal worms from petco, a plastic shoe box sized container, and a few cups of oatmeal. There have been several times had to "feed the birds" because I had so darned many of them! But not too much. You can always put them in a container in the fridge to keep them from turning into beetles and feed them later.
Never had anything kill them all off, although I have thrown out big scoops out of containers because mold got into the oatmeal.