Using it as substrate. Should they be eating their substrate? For rats you cant feed any food that has red dye because it builds up in them. When snakes it the rat it kills the snake. Personally I would not be giving caffiene to my reptiles..... prob lead to very active and odd tempered lizards. I know for meal worms you can just cover the bottom in oatmeal and come out with a good amount of larva.....

Dubia feeder roaches are super easy to do. It is my feeder insect of choice. If you get more infom post it, I am very interested in hearing your outcomes. Possible post pics?