Just started hatching quails. We have been somewhat successful but for some reason a few chicks after a few days start stumbling and kick legs in air, then eventually die. We have had 4 do this out of roughly 30. I use pine bedding, we use 30% protein chick starter which I grind up even finer. The best seems to be fine as they aren’t huddling or trying to get out to edges. We keep fresh water and food available at all times.