We have 6 girls, all the same age, got the all at the same time. Always stick together, no obvious top hen which we have had before so I don't think there is any bullying.
Just the last few days, one of the girls has often been on her own, all puffed up and sitting still in the middle of the grass, almost as if she is going to lay, but she definitely is still laying in the nesting box. Definitely apart from the rest of the flock most of the time.
Having said that, she does trot over when you come down with the treats etc. The first time I saw it, I thought perhaps she was a bit cold. But it's been a few days now, she is the only one doing it and it seems out of character.
Should I worry?