I just read something in a number of different research articles. Precocial species such as chickens who have a biological imperative to be up out of the nest and running ASAP...they enter arrested development while they wait for the siblings to be laid over the next week. But inevitably, some development does occur. Researchers have determined that despite the development of the earlier eggs, ALL THE BABIES tend to hatch within just two hours of each other. How? They communicate. By clicking. The clicking slows down or speeds up based on whether the babies are ready or not-and then they all pop out at the same time. The rub is, the eggs MUST be touching. They can’t click and peep to each other and receive sensory input unless they are touching. Even a few centimeters apart makes it impossible to hatch all together. The same holds true for artificially incubated babies. So. My babies just hatched and nobody is due for another week. Somebody needs to go on lockdown and do the experiment!!!