Mine just eat a hamster and gerbil mix, they will also take rat pellets and love millet spray and monkey nuts!
I haven't really tried a lot in the way of treats or fresh foods such as fruit or veg as i haven't really researched them in that area, but they've done great on my above diet, males can get a little weighty, so peanuts, sunflower seeds and other fatty foods may need to be kept stricly as treats to prevent chunky monkeys
