Babies are so much fun! I raised a bunch of Silver-laced Wyandottes from two days old this past spring. I would put a single lettuce leaf in there to amuse them. Or a few blades of grass. They didn't eat much of it, but I read that green placed in with them keeps them focused and discourages pecking. I also placed a small container of fine sand in there, and was amazed at how much they consumed. A slice of melon, or pear or grapes cut in half will also keep them amused as well as get them used to diversity. Always in tiny amounts, though.
I had them in an appliance cardboard box in the spare bedroom. I used peat moss for bedding, and while the chicks loved it, even dirt bathed from two weeks on, the dust got in everything. It was great, though for odor control, being so absorbent. But next time I'll use pine shavings even though they sure did enjoy their little baby dirt baths!