About 2.5 weeks ago I gave my silkie some chicks because she was broody. She took them all right away and has been an amazing mother. This morning i found one of the babies dead in the nest. What could have happened? When i first got them i thought i saw a small spot of blood in the poo but never saw anything since and all of the chicks were very active and happy so i didn't treat. It has literally been raining for at least a week here and sometimes rain leaks into the coop but i scoop out the wet bedding in the morning and evening if there is any. They are all in a private coop set up next to my main coop to protect them from my main flock. I did start treating with corid today just to be safe. How long do i treat them? What could have happened? All remaining babies appear to be very healthy. Also could it be food related? Im feeding starter dumor feed. My other batch of chicks are almost 7 weeks old and one of them had wry neck which i saved and they are eating the same feed. Ive never had a problem with any chicks before but ive never fed this brand of starter feed either.