To answer Linda's question from my comments of the last post, yes, chicks peep before they hatch! They have an air cell in the egg that they use to breathe when they're getting ready to hatch.
And guess what?! One chick has pipped his egg! A pip is a small crack in the shell that is the first part of hatching. The chick will pip and then rest for a bit. Next comes the zip. Zipping is when they start at the pip and crack a line all the way round the egg (looks like they're unzipping the egg). It can take a while from pip to hatching, so I'm not sure if I'll have a chick by the end of today or by tomorrow.
I apologize for not having pictures, but I just couldn't get it clear enough for you to see the pip.