Look at the basics.
Heat. What is your brooder temp? Is the brooder draft free?
Water. Is the water fresh? Did you clean the waterer before using it? Was it rinsed well?
Food. Is the grain fresh? No mold?
Yes I know I'm a little late but the next person reading this thread may be helped.
It looks like the incubator is the R-COM 20.
I have the same one. You will want to completely cover the bottom with paper towels in the future.
It gives them the traction they need to keep their legs under them.
Peter
Or maybe this would be better.
WASCO True-Tan Bird Tan
Or Borax dry tanning method. http://www.flyfishingwis.com/html/tying_materials.html#Drying%20and%20Tanning