It's cracked tank I can't use for fish, so it's open for raising feeders. My hopes was to raise a nice batch of fruit flies and not happening. Simple setup of wood fibers sold for fruit flies and then I toss in somewhat spoiled fruit for the fruit flies to eat. I already have a heating light on order for my crickets( which also won't breed due to temps)...Since I'd rather not buy more heaters, I wonder if I put the fruit flies tank next to the cricket tanks.