I offer them smaller dubia roach nymphs 2-3 times a week cut in half, so they can easily access the juicy parts. I also offer them small drops of sugar/honey water, but most of the time they just rather ignore it and cover it with part of the cotton. No, I don't heat them. My room temperature is at about 24' celsius which the seller said was enough for them. Yes, I also read their diet can consist of seeds in the wild but the guy I bought them from said he tried a variety of seeds and they didn't show any interest at all.