I'm so freaked out-two of my chickens, one a year old Barred Rock hen, the other a middle-aged silkie hen, both very healthy, died randomly. The year-old girl on Saturday, the other today. They were both healthy and acting normal, then I just found them lying on the ground-the first one was already dead when I found her, the other was just lying on the ground helplessly and died a little while after.Neither had any kind of abrasion. What might be wrong? What can I do to protect the others? I have a big flock of 35+ hens, and I don't want to lose any more! They are my pets! They are on a layer pellet diet supplemented with cracked corn and always have access to both that and clean water. I am not an expert on chickens-please help!!!