Any one know about growing fruit flies? I bought a culture about a month or so ago. It was already full with adult flies. I tossed them into my tanks and kept the bottle in case, while sure enough their are hundreds of maggots in it now. They are in various stages ( some new fruit flies too). They have eaten up almost all of the medium that was in the bottle. I was just wondering if I wanted to keep the culture going what can use as a medium? I was thinking old fruit but that would get mouldy?