Fertilized chicken eggs are in a state of suspension. Bobbi J is right, they do not begin to develop. The reason is it takes about 25 hours for a hen to lay an egg. Sometimes even today in people's flock, the natural process takes place. A hen will hide an egg, the next day she slips back there to her hidden nest, lay another egg. Pretty soon she will have a clutch of eggs, when the clutch looks to be the right number, she will begin to set.
At this point she is a broody hen, with incredible high hormones. Her whole personality changes and even her posture. She sets on those eggs, low and flat, and will puff and growl if anything gets too close. She will only get off the nest once a day to eat and poop. After 24 hours of being warmed to close to 100 F, the eggs begin to develop and grow. All the eggs are in the same state of development, regardless that some were laid a few days ago, and some might be close to a week old. What nature has allowed, is for all the eggs to start at the same time, so that they hatch at the same time.
When they hatch, she will leave the nest in about 12 hours, taking the live chicks with her, leaving any duds, create a new nest usually back with the flock. So you see, she needs those eggs to develop all at the same rate. She cannot be tied to a nest, trying to get the last laid eggs to hatch, while the live chicks are running around needing protection.
This is also why, if you get a broody hen, you need to add the clutch all at the same time.
I am of the opinion that chickens are flock animals, and need to be together. I am confused by the statement that he can protect them through the fence? He cannot rule his girls unless he is in there with them.
Mrs K
