A quick run through to help work out what could be wrong with her,
We have 13 chickens of differnt breeds that we purchased from 2 different places, we have had them for just over 2 weeks so are not really familiar with behaviour although we have read and discussed alot with people.
They were all doing great, happy and settled together after a couple of rows, then yesterday afternoon i noticed one of the Light Sussex acting a little odd, (she was the most shy one out of them all) when i called them and threw in some mixed corn, a couple of hours before bedtime as usual, they all came running like mad things, but not her she stayed on her own where she was, i watched her for a while and she was concertinaing her neck into her body (beak closed) then moving it forward to the original postion her beak was open, she kept doing it, slowly walking around.
One of the other hens came over a grab hold of the feather on top of her head really pulling hard not letting go, she didnt try running away just ducked down abit until it let go.
I decided to remove her from the rest and put her in her own small run so i could watch her better, she was eating the grass, mixed corn and drinking water ok. So at bedtime when most were already in the coop i put her back in the run and she took herself off to bed.
This morning when i first let them out she was the last one to come out and although seemed quiet was not doing the neck/beak thing, she walked away from the others who were munching and drinking and went up the side of the coop in the run.
I have had things to do today so have not been able to watch her much, but checked her an hour ago once home and she is back doing the same opening and closing her beak but not the neck concertinaing, i have again removed her from the others and she is eating grass, layer pellets and drinking ok.
I have felt her crop this afternoon and it feels round and grainy not bloated. Her poo is normal i checked it no sign of worms.
She is about 19 weeks old, she is not laying and has not yet, her wattle and comb are pink and small compaired to the other Light Sussex that we purchased at the same time, who was ment to be the same age, the other is not laying but i think will be soon as her comb and wattle is red and larger.
I hope someone will be able to help with advice, she'll be off to the vet tomorrow afternoon if she does not get any better.
Thank you.