Laying away from home

This is Attila, our light sussex hen. She is, jointly with one of the rhode rocks, our oldest bird, about 3 years old. She stopped laying over winter and we weren't sure, given her advancing years, whether or not she would start laying again. Well, earlier this week, I saw her pop over the fence into the wooded embankment next to our allotment where minutes later she produced an egg, next to one presumably from the day before that I had missed. Since then she has laid every day. I know that because she has chosen to continue laying in the same spot, away from the nest boxes in the henhouses. She is not the only hen guilty of this crime. Of the 11 eggs produced today, 6 were laid behind the haystack, plus Attila's on the embankment, leaving only 4 deposited in the henhouses.