Normal droppings rule out Coccidiosis.
EDT: or I guess not. I defer to you, Eggsighted.
Coccidiosis article.
Your picture makes me think they're cold. They should be spreading out more than that. Do you have a higher wattage light bulb? Can you measure temperature in there? It should be about 90-95 for the first week, decreasing by about five degrees for every week after. (so 85-90, at this point)
Another problem that's easily solved is nutritional deficiency. Do you have any poultry vitamins or do you have access to a close Walmart or feed store? Low-iron baby vitamins will do in a pinch; but if you can get chick vitamins (with or without electrolytes) it's better. If you have vitamin B complex tablets in the house, please just crush and add them to their water now. B is important
Electrolytes are available at feed stores, but you can make up a quick batch of your own with 2 tbsp corn syrup/sugar/or molasses, 1 pinch salt, 1 tsp baking soda, 1 pt. water. It's a quick energy boost and it will help hydrate them.
Good luck. Keep us posted.