New Baby Chicks!!

We just got our first batch of baby chicks today. They're only about four days old: two Leghorns, two RI Reds, and two Americaunas. They're all set up in their box with their light and food and water, just like I remember from when I was a kid.

But I'm worried about one of the little Americaunas. It's being less active than the others, seeming to fall asleep on its belly with its head stretched out. It wakes up sometimes when it's stepped on. Could it just be tired, or should I be worried?? We've only had them for a couple of hours at this point.

Thanks, and I'm sure excited!
--Dana