Aside from being hard to gut load, do houseflies have much nutritional value at all? My frogs love anything that flies, moths get them racing all over the terrarium to catch them and when I added flies they went simply nuts. I plan to have roach colonies but it will be a while until the colony becomes big enough to supply a steady food source.

I have a lot of different ways to gut load flies as best as you can but if anyone has any suggestions to help add to their nutrition value it would be appreciated, aside from the obvious dusting.

Sorry if this has been covered but a dozen searches on here and I am no closer to the answer. Google searches provided no answers.