I have 2 large brooder bins in my living room of chicks, both are 10-11 days old. One has 10 orpingtons, other has 19 brahma chicks, each came from different breeder. They were shipped to me. I started them on paper towels for a few days, moved them to new pine shavings. Temp. is correct- verified with thermometer. Have medicated chick starter. Clean water several times a day- gave the sav-a-chick right after shipping, went to normal water, started back on sav-a-chick this morning. No pasty butt, poop looks normal. They seem normal, active, growing, eating, drinking, then I suddenly find one dead. Lost one brahma at 6 days old, another brahma last night, an orpington this morning. I watch them very carefully and am getting concerned, or is this 'normal' loss? Thanks.