I was out of town and my husband called and said he found one of my young pullets dead by the coop. No blood or any sign of something attacking her. He said she seemed healthy the day before. That was 2 months ago. Last month, I went out of town again and when I got back, my frizzled Naked Neck was just sitting under a heat lamp all day....not coming out to get treats or anything. I put her in a crate in the garage and two days later she died. She had bright healthy looking eyes, no discharges, no mites/lice. So now, I was outside and I saw my Black Australorp just sitting under a bush. All the other chickens are out foraging. I went out and threw some scratch to see what she would do. She just sat there until I picked her up and set her down near the scratch.. She ate a bit, but then went and sat down again. Again, no discharges, no lice/mites, color looks good. WHAT IS GOING ON???? What do I need to check for? How would I check for worms? These birds have no coughs, no gasping, just all seem healthy and then they are down. Any suggestions?