With in the same day of the chickens hatching some are dying the white ones are good but it is just the black chicks we are having a problem with. The last one had a large lump on it's belly and could not walk it's feet were curled in. Another just died it seemed ok. One that has just hatched seems very week only moving a little bit but no churping. 2 others have hatched and they are fine and very noisy. What could it be have we done something wrong we did't have this with the first batch.