1) Buff polish chick, 2-3 days old, seemingly underweight at death but not day 1. 2) The chick seemed fine yesterday and this morning. Would respond to the brooder being nudged, ate with the others. Then I go to check this afternoon, and I nudge the box, and everyone but this one stands up. The others are a day or two older than this one, which is why I thought he was sleeping more. But today in the span of less than 8 hours he went from standing to barely able to stand, to not standing, to laying sprawled on his side. When he was barely able to stand, he was able to take water when I dunked his beak in the waterer; he'd toss back his head and swallow like the others. About 20 minutes after that he couldn't lift his head, but he could swallow when I put a drop of water at the edge of his beak. Couldn't stand or lift his head by then, but was still squeaking up a storm every time I moved or touched him. I was mixing up a soft, wet mash to try to feed him when he just died. 3) Fine this morning at 9am when I looked in on them, dead at quarter after 5pm. 4) No sign of injury or trauma, but he was missing toes when born, had a very long, arduous hatch, and what seemed like a very small head crest and wings. 5) The chick wasn't kept in any other conditions than the other 4, who are all chirping and very active, moreso than this chick ever was. They are in a brooder with an under-floor heating pad and a soft reptile sunlamp. They have pine shavings which I don't see them peck or scratch at unless they drop food bits, which they grab and then go back to the feeder. The feeder is a chick safe red and white one and the waterer is the a matched set. The only thing I can think is that I cleaned shavings from the waterer and set them in a corner over the under-floor pad to dry. I did not personally observe anyone going after them, but it's always possible. 6) A very finely ground chick starter from a red and white type feeder and filter water from our fridge. I observed all the chicks at the feeder last night, but I don't know about water, none of them drink often. 7) I haven't observed this particular chick pooping so I can't describe that. The others all have off-brown and white droppings, sometimes very solid, sometimes a little foamy for lack of a better word. 8) I didn't get a chance to administer treatment, unfortunately. I separated him and gave him a little water with a syringe and had just finished boiling an egg to mash into some feed with warm water when he died. What I am wondering is what acts very quickly and causes loss of motor control like this? I've read mareks and botulism can, but there's no way for them to have gotten marek's unless it spontaneously comes into creation; there are no other chickens in or around my house, and I hatched them myself at my house. If there was something in the feed, I would think at least 1 other chick would be showing symptoms, but their demeanor is entirely different than this one's and their poo looks just fine to me (they make more than enough to see that, sheesh) Obviously there's nothing I can do for the chick that died, but I am interested in knowing what to look for IN CASE it is something that could get to the other chicks.