I hatched 15/16 eggs on Tuesday/Wednesday. Today I took the last egg out of the incubator and float tested it....no movement and it sank. I opened the egg and found a dead fully developed chick inside. The yolk was gone and the shell was clean inside. I know that the temperature and humidity were right because I did get 15/16.......so why did this one not make it? I know this stuff happens, and I am not upset by it...I just want to make sure if it was something I did that I don't do it again. Any ideas?