What can I do to expose my chicks?

You can cut a chunk of sod and put it in there. They will eat the grass and scratch. If you are giving clippings, keep them very short- maybe 1/2 inch at that age, and then maybe 2-3 inches long for adults- to prevent impacted crop.

It is easier to let them eat the grass not clipped (as in, they are out on pasture), for then they snip off the perfect length for themselves. I do give grass clippings too.

Coccidiosis is something to watch for though- be on the lookout for lethargy, bloody poo or diarrhea, not eating or drinking, feathers fluffed up after exposure to soil. It is treatable and can be fatal within 24 hours. They will become immune to the cocci in the soil, so it usually only affects those under 8 weeks of age.

I let mine out to pasture at three weeks, and they are free to come and go from the heat lamp inside the shed as they like. Before three weeks I have found that they tend to stand around outside and shiver, not being self-aware enough at that age to realize they are supposed to go back through the door to warmth.

I do cover the pen with netting at that age to protect them from hawks and have the area fenced. I don't let them out all day at first- only brief times and then work their way up to all day.

They need some grit to eat grass and treats. Sand works well for tiny chicks, and they will find gravel in the soil if free ranging as they get older. Or you can buy grit at the feed store. They have chick grit and older chicken grit (size #3).