I had one chick dead everyday for four days on the trot. The babies were perfect and happy when they went to bed. There didn't seem to be any reason for what happened. This year I delayed putting them in with the big hens untils they were 9 weeks old and so far, touch wood, they seem to be surviving.It's horrible when you find them dead so you have my sympathy but you just put it down to experience and start again.