When we got my chicks last Friday, I asked the guys opinion on sand in the brooder. He advised against it because they could choke. Has anyone had this experience? I have sand, but as of now it is covered in paper towels. The other thing is I have two girls that keep getting pasty butt (I think). When they poop it gets stuck in their fluff. They are an americana and a Cochin. I can't seem to get the gunk off. I have tried warm damp paper towels. They seem healthy and happy besides that. What causes this?