they like darkness, i didn't see any change in it with complete darkness so it doesnt seem like a negative or positive. . .well the positive being that you dont have to look at them perhaps, or outta sight outta mind. . . i really dont know.
my dragons can eat about 15 a day, 3 times a week. . .however they are adults so i feed them less then when they were juvies. . . with them i messed up and didnt start my colonies early enough so they were past their growth spurt before anything was established.
they will generally eat until they are full, which could be anywhere from about 15+