Thank you all for taking the time to respond.
The kids make it so much fun and are so funny about caring for the chickens. For months they have been going out first thing to clean the coop every morning (and now to check for eggs too). I didn't think the daily coop cleaning would last as long as it has, but I venture to guess that we probably have one of the cleanest coops on the east coast! I don't expect it to continue daily, but am pretty confident they are building in some pretty good habits that will last.
When the chickens started laying, it was a game to figure out which chx laid the new egg. They would camp out each day waiting for the layer and were so amazed at the actual egg laying process. Looked up the whole works about how an egg is produced, etc so they could see the science and wonder behind it all. So neat!