there will be a lot of people her who disagree with me but I put mine out at 1 week old (nights around 50) with no light. They are doing fabulous. Healthy, happy & foraging adn not half as stinky as my friends who got hers the same day as me. Her's are slightly larger so I think that mine are using some energy for body heat, but I find it a good thing.
I'm curious what hatchery you got your meanies from . . . although I too suspect the empty feeder is the cause for the aggression.
I'm curious what hatchery you got your meanies from . . . although I too suspect the empty feeder is the cause for the aggression.