I've got a brooder full of Speckled Sussex and Delaware chicks, 3 days old. I let them get too cold last night and lost some, but brought them inside this morning and their temperature has been in the correct range all day now. But I keep on losing Sussex chicks! Some of them are hopping around, eating and drinking and sleeping in the pile, but some of them just lie down and die. Each chick has had its beak dipped into the water to show it what to do, but I admit I wasn't vigilant about making sure they understood and took a drink unassisted. Every time we find a chick lying listlessly on the floor of the brooder, we take it and dip its beak in the water, then hold it to warm up (human body temperature is only a little warmer than the brooder temperature, but it feels like the nice thing to do!) for at least 20 minutes. This treatment has saved maybe a couple of chicks, but we've lost several. In any case, the Sussexes and the Delawares all got the same treatment, but the Delawares aren't dying. Yes a couple of them died last night in the cold, but since we've brought them in the Delawares have been healthy and strong. Are Delawares just a hardier breed, or did the hatchery send me a bad batch of Sussexes? History: got the box of chicks from the PO yesterday afternoon and stuck them in our brand-new homemade brooder on the back porch: wire mesh floor, wire mesh front, solid walls for sides, back, and roof. Heat lamps on the front, thermometer in the back. Dipped each little beak in the water (which has a splash of apple cider vinegar in it), then left them alone for a few hours. Noticed that they weren't settling down, so we brought out the terrarium (glass open-top box, like an aquarium) that we successfully raised smaller batches of chicks in; put chicks in terrarium and put heat lamps on top of it, with thermometers on each end (one under heat lamps, on on the other side which was much cooler). Thermometer showed an acceptable temperature on warm side, and chicks settled down to sleep, so we went inside and went to sleep. In the morning, checked on chicks. It had gotten much colder in the night, and the warm side was only about 70 degrees! Poor chicks! There were 3 or 4 dead, with another 3 or 4 listless. Brought terrarium inside and it quickly warmed up to 90 degrees on the warm side. Most of the chicks seemed to be fine, and we did the best we could with those listless ones but we only saved one, the others died pretty quickly. But as I said, I keep on noticing more Sussexes going listless.