My chickens are 5 months old. Not all are laying. But the few that are, they don't seem to sit on them at night. I go out and the eggs are cold. Will this change? I have 23 chickens. 1 hen is protective when I go to gather the 2-3 eggs. So I left the first time 5 eggs laid yesterday in the nest, but this morning they were cold. Was is the temperature that an egg should keep in the nest? I'm new can you tell.