One of my 20 week old light sussex hens died today! I am new to rearing hens and feel awful, due to my lack of knowledge. I got her three weeks ago and she was always a little sheepish, timid and generally tired compared to the others. I would notice her constantly falling asleep on her feet. Not fussed about foraging for food. Then today I came home to find an extremely tired bird that would get up to leave the run. I tried temping her with scraps. But she would eat and has died. I don't know what gas happend. Can anyone help? My other hens are the same age and seem to be thriving. Fingers crossed.