Hello! "Newer" chicken owner here. This is our first round of chicks. We live in an urban area. Hatched late February. Not laying yet. 36 hours ago- one of our chicks was lethargic, not eating/drinking, eyes closes, laying there. Wouldn't move. Woke up this morning and she had died overnight. Same general symptoms as "egg bound"- although they are not laying age yet. Husband said he picked her up last night and she "pooped" a pale yellow almost pus-like discharge. No foul smell. Other 3 seem "fine". Acting normal. As I was talking to them a few minutes ago I notice black, dirty looking specs on their tail feathers. Are we dealing with mites? Not sure if that took the other one down. Would it happen that fast? We're perplexed. Also, looking at Diatomaceous Earth and getting conflicting information. Could this (dust particles) be bad for the birds? For my dog? For us? Not sure what we should do.